International Law and the Russia–Ukraine Conflict: A Comprehensive Legal Assessment

​Bản tiếng Việt tại đây: Luật pháp quốc tế và xung đột Nga-Ukraine

International Law and the Russia–Ukraine Conflict

(A Comprehensive Legal Assessment)

Author: Dr., Lawyer Nguyen Quang Anh

Director of Sao Viet Law Firm LLC

Overview

Russia’s military intervention in Ukraine, launched in February 2022, represents one of the clearest breaches of the post-1945 international legal order. By attacking a sovereign neighbor without provocation, Russia violated fundamental norms of state sovereignty and territorial integrity enshrined in the United Nations Charter. The UN General Assembly overwhelmingly condemned the invasion as an act of aggression and demanded Russia’s immediate withdrawal. This marked the broad global consensus that Moscow’s actions lack any lawful justification. The conflict—the largest in Europe since World War II—has led to massive devastation, thousands of civilian casualties, and a humanitarian crisis, all while testing the effectiveness of international law and institutions. What follows is a scholarly legal assessment of the conflict, addressing the jus ad bellum (legality of resort to force) and jus in bello (law governing conduct in war), comparisons with past precedents (notably Kosovo), and proposals for legal reforms to address gaps revealed by this war.

Legal Analysis (Jus ad Bellum and Jus in Bello)

Jus ad Bellum: Legality of Russia’s Resort to Force

Under international law, states are categorically prohibited from using force against the territorial integrity or political independence of other states (Article 2(4) of the UN Charter). Only two narrow exceptions exist: a state may use force in self-defense if an armed attack occurs (Article 51), or if the UN Security Council authorizes force to maintain international peace. Russia’s invasion of Ukraine had no Security Council authorization (indeed, Russia’s veto precluded it), so Russia sought to justify its actions as self-defense and humanitarian necessity. These justifications, however, find no support in law or facts.

Self-Defense Claims: President Vladimir Putin, in his 24 February 2022 address launching what he termed a “special military operation,” explicitly invoked self-defense under Article 51 of the UN Charter. Russia even sent a formal letter to the Security Council claiming its actions were in accordance with Article 51—a token nod to legality despite the evident reality that no armed attack by Ukraine had occurred. International law only permits preemptive self-defense in the face of an imminent attack, under the stringent Caroline criteria (the threat must be “instant, overwhelming, leaving no choice of means, and no moment for deliberation”). Ukraine posed no such immediate threat to Russia. Moscow’s references to a future Ukrainian NATO membership or Western weapons buildup were at most speculative, not an impending armed attack. As scholars note, fears about NATO’s “eastward enlargement” do not create a legal right to attack a neighbor—countries are free to choose their alliances, and such political grievances fall far short of the necessity required for lawful self-defense. Thus, Russia’s invocation of anticipatory self-defense stretches the concept beyond recognition and has been widely rejected. Even during the U.S.-led 2003 Iraq invasion, which was premised on preemptive self-defense, the international community refused to bless such a doctrine. Russia’s war on Ukraine similarly finds no shelter in self-defense: it is aggression, prima facie unlawful.

Humanitarian Intervention and Genocide Allegations: Anticipating global outrage, Moscow also alleged that it was acting to prevent a “genocide” against ethnic Russians in Eastern Ukraine. This claim attempted to echo the rhetoric of humanitarian intervention or the “Responsibility to Protect” (R2P) doctrine. However, Russia’s narrative of a Ukrainian “genocide” in Donbas had no credible evidence. International monitors, including the OSCE, observed no such systematic attacks on the Russian-speaking population. In March 2022, the International Court of Justice (ICJ) examined these allegations in a case brought by Ukraine and found no factual support for Russia’s genocide claim, ordering Russia to halt its military operations. Legally, unilateral humanitarian intervention without UN approval remains highly contested and not established as an exception to the prohibition on force. NATO’s 1999 Kosovo intervention, often cited as a precedent, was described by its supporters as a sui generis moral action rather than a new legal right, and it was not codified into law. Russia was among the states strongly opposing that intervention as illegal—a stance that makes its own “humanitarian” rationale in Ukraine flagrantly inconsistent. In short, invoking humanitarian motives cannot legalize Russia’s use of force, especially when the supposed atrocity (genocide) is a fiction.

Intervention by Invitation & Remedial Secession: On the eve of the invasion, Russia took the extra step of recognizing two breakaway enclaves in Eastern Ukraine (the self-proclaimed “Donetsk and Luhansk People’s Republics”) and promptly claimed to intervene at their request. In theory, military assistance given to a sovereign state at its invitation can be lawful—but here the “states” in question were actually parts of Ukraine under the control of Russian-backed separatists. No UN member state (besides Russia and Syria) recognized Donetsk or Luhansk as independent; their recognition was a unilateral Russian creation. International law does not permit a state to fabricate a puppet entity and then invoke its consent to justify invasion. Furthermore, Russia suggested that these regions—and later, other Ukrainian territories like Crimea, Kherson, and Zaporizhzhia—had a right to secede and join Russia, supposedly as a form of self-determination or “remedial secession” due to Ukrainian government abuses. This argument again echoes the Kosovo case, where Kosovo’s declaration of independence was defended by Western powers as a remedy for Serbian oppression. However, under prevailing international law, there is no general right of unilateral secession except in colonial contexts or possibly the most extreme cases of persecution. Even Russia itself, in its submissions to the ICJ’s Kosovo advisory proceedings (2010), argued that remedial secession is only conceivable in truly extraordinary circumstances such as genocide. Those circumstances plainly did not exist in Ukraine. As noted, claims of “genocide” or mass atrocities by Kyiv were unsubstantiated propaganda. Moreover, the will of the local people to secede was dubious: Russia’s orchestrated referendums in occupied territories cannot be considered bona fide expressions of self-determination. They were conducted under military occupation, with no independent observers, and accompanied by widespread reports of coercion and population displacement. The UN General Assembly, in October 2022, declared these sham referendums “invalid and illegal” and affirmed Ukraine’s territorial integrity within its internationally recognized borders. In sum, neither the creation of proxy states nor appeals to self-determination legitimize Russia’s territorial grabs.

All told, Russia’s use of force against Ukraine constitutes a textbook case of “aggression”—“the supreme international crime,” as defined since Nuremberg. The jus ad bellum analysis leaves no doubt that Moscow’s justifications (self-defense, prevention of genocide, and invitation from separatists) are pretexts unsupported by law or facts. The near-universal international response underscores this: within days of the invasion, 141 states in the General Assembly voted to deplore Russia’s aggression and demand withdrawal, and in October 2022 an even larger majority condemned Russia’s attempted annexations of Ukrainian territory as illegal. Such clear condemnations by the world’s nations reinforce the peremptory character of the ban on aggression and demonstrate that violations, however egregious, do not change the rule—they only reaffirm the international community’s commitment to it. Russia, notably, has not openly repudiated the Charter framework; by cloaking its actions in (implausible) legal justifications, it tacitly admits that acting outside the law would carry even greater stigma. This confirms a sobering point: the law against war remains intact, but its enforcement depends on collective resolve. In Ukraine’s case, that resolve has materialized in the form of sanctions, arms support to Ukraine, and emergency measures in the UN General Assembly—a reflection of law’s enduring if strained relevance in the face of raw aggression.

Jus in Bello: International Humanitarian Law in the Ukraine Conflict

Once hostilities began, both Russia and Ukraine became bound by international humanitarian law (IHL)—the laws of war governing conduct during conflict (chiefly derived from the Geneva Conventions, their Additional Protocols, and customary law). The Ukraine war is an international armed conflict (between states), which triggers the full array of IHL protections for civilians, prisoners of war (POWs), the wounded, and other non-combatants. In this domain, the legal issues have centered on widespread allegations of war crimes and the responsibility of parties (and individuals) for those violations.

Protection of Civilians and Civilian Objects: IHL’s cardinal rule is distinction—belligerents must at all times distinguish between combatants and civilians and between military targets and civilian objects. Deliberate attacks on civilians, or attacks that cannot discriminate between civilians and combatants, are war crimes. In Ukraine, Russian forces have repeatedly been accused of violating this principle. The UN’s Independent Commission of Inquiry on Ukraine, as well as numerous human rights organizations, has documented a pattern of indiscriminate and disproportionate attacks by Russia. Residential areas, schools, hospitals, and critical civilian infrastructure have been shelled or bombed, often with no evident military objective. For example, an attack in April 2023 on an apartment block in Uman killed 24 civilians (mostly women and children) and wrecked the building. Such strikes on densely populated areas suggest a disregard for the IHL duty to take all feasible precautions to spare civilians. Amnesty International’s on-the-ground investigations in 2024 found that Russian forces have deliberately targeted civilians and civilian infrastructure, including far from frontlines, in ways that “amount to war crimes.” One egregious instance was a Russian missile strike on Okhmatdyt Children’s Hospital in Kyiv in July 2024, which caused massive damage, killed two people, and injured over a hundred (many of them children). No Ukrainian military presence was found near the hospital—pointing to an unlawful direct attack on a protected medical facility. This attack was chillingly reminiscent of Russia’s earlier bombing of a maternity hospital and a drama theater sheltering civilians in Mariupol in 2022. Hospitals enjoy special protection under Geneva Convention I; bombing them with no military necessity is a flagrant war crime.

Atrocities in Occupied Areas: As Russian troops seized areas such as Bucha, Irpin, Mariupol, and Izium, reports emerged of summary executions, torture, enforced disappearances, and sexual violence against civilians under their control. The UN Commission of Inquiry’s reports confirm many of these atrocities: Russian authorities have used torture “in a widespread and systematic way” in detention facilities, often brutally beating and electroshocking detainees, sometimes to death. In one documented case, prisoners in a Russian-occupied area pleaded for medical care for a cellmate who had been tortured into respiratory distress; Russian guards refused, and the victim died within an hour. Rape and sexual violence by Russian soldiers have also been recorded, frequently accompanied by additional sadistic acts such as beatings and threats to the victims’ lives. A UN report recounts the ordeal of a 75-year-old woman who was beaten and raped by a Russian soldier; her ribs and teeth were broken in the assault. Such conduct violates peremptory norms of IHL and constitutes grave breaches of the Geneva Conventions (willful killing, torture, inhuman treatment). Rape and sexual violence in war are specifically recognized as war crimes and potentially crimes against humanity when part of a widespread or systematic attack on civilians.

Forced Deportations and Cultural Erasure: Another disturbing facet has been the deportation of Ukrainian civilians—especially children—to Russia. Transferring or displacing the population of an occupied territory into the occupier’s own territory is prohibited by the Fourth Geneva Convention. Yet Russia has evacuated or outright abducted thousands of Ukrainian children from occupied regions under the guise of “humanitarian” evacuations or adoption programs. The Commission of Inquiry concluded that such transfers were often forced and conducted without families’ consent, amounting to unlawful deportation, which is a war crime. In March 2023, the International Criminal Court took the unprecedented step of issuing arrest warrants for President Putin and his Children’s Rights Commissioner, charging them with the war crime of unlawful deportation and transfer of children from Ukraine to Russia. The ICC judges found reasonable grounds to believe that Putin bears individual criminal responsibility for these acts, both directly and under the doctrine of superior responsibility for failing to prevent or punish subordinates. This is a landmark in accountability: the head of state of a major power is accused of personally committing war crimes—a powerful reminder that even top leaders are not immune if they perpetrate egregious IHL violations.

Methods of Warfare and Weaponry: Observers have also raised concerns about certain weapons and tactics used. Indiscriminate shelling with heavy artillery and multiple-launch rocket systems in urban areas, reported use of cluster munitions and anti-personnel mines by Russian forces, and attacking critical infrastructure (power grids, dams) in ways that cause disproportionate hardship to civilians all violate the IHL principles of distinction and proportionality. Starving out cities or denying humanitarian relief can amount to prohibited starvation of civilians as a method of warfare. While Ukraine’s armed forces also conduct military operations (including in populated areas, since they are defending cities), Russia’s far greater firepower and often intentional targeting of civilian-heavy sites have made civilian suffering overwhelmingly a result of Russian tactics. As one analysis put it, Russian forces appear to use atrocity as a strategy—deliberately terrorizing civilians to break the population’s will to resist. Such a strategy, apart from its moral repugnance, squarely contravenes the law of armed conflict.

Compliance by Ukraine: It is important to note that IHL binds both aggressor and defender. Ukraine must also adhere to the laws of war. There have been instances where Ukrainian forces have been accused of misconduct—for example, isolated cases of abuse or execution of Russian POWs caught on video or the indiscriminate shelling of areas held by Russian proxies. Ukraine’s government has generally acknowledged such allegations and pledged to investigate and prosecute violations. The UN inquiry found some violations by Ukrainian authorities, such as mistreatment of persons accused of collaborating with Russia. These incidents, while concerning and unlawful, appear sporadic rather than systemic. There is no equivalence between the scale of Russian violations and Ukraine’s. Ukraine has a far better record of cooperating with international monitors and seeking to punish wrongdoing in its ranks, whereas Russia has systematically denied or covered up its forces’ crimes, even bestowing honors on units accused of massacres. Nonetheless, the principle of equality before the law in war means any breaches by Ukraine are also condemnable and subject to legal accountability. All parties are bound by Common Article 1 of the Geneva Conventions to “respect and ensure respect” for IHL in all circumstances.

Accountability Efforts: International law not only sets rules for warfighting but also demands accountability for serious violations. In the Ukraine conflict, multiple avenues for justice are being pursued. Apart from the ICC’s investigation (which, in addition to the child deportation charges, is examining other war crimes such as deliberate attacks on civilian targets, torture, rape, and executions), Ukraine’s own courts have initiated war crimes trials (including convicting a few Russian soldiers captured after committing murders). Other countries, invoking universal jurisdiction, have opened cases to investigate atrocities in Ukraine. The evidence collected by the UN Commission of Inquiry—which has explicitly stated that war crimes have been committed in Ukraine—will be crucial for future prosecutions. The commission’s October 2023 report not only catalogued Russian forces’ atrocities but also stressed the need for comprehensive accountability “with full respect and care for the rights of the victims.” This implies not just criminal trials, but also reparations and truth-telling.

It should be noted that beyond war crimes, the crime of aggression—the unlawful initiation of the war itself—is under discussion for prosecution. Because neither Russia nor Ukraine has accepted the ICC’s jurisdiction over aggression (and Russia would veto any Security Council referral), there are proposals to create a special tribunal to hold Russia’s top leadership accountable for the act of aggression, which is considered the root cause of all the other crimes. This would fill a gap in the international legal system’s ability to address the gravest breaches of the peace.

In summary, the jus in bello dimension of the Russia–Ukraine conflict has been characterized by egregious Russian violations of humanitarian law and a concerted international effort to document and respond to them. The conflict reinforces both the critical importance of IHL and the challenges of enforcement. It has demonstrated that even a major military power cannot escape scrutiny for atrocities—indeed, global outrage and the machinery of justice have mobilized in unprecedented ways (including against a sitting Security Council permanent member). At the same time, the suffering inflicted on civilians shows the tragic consequences when IHL is flouted. The war may prove to be a turning point that either strengthens the norms (through accountability and reform) or, if impunity prevails, dangerously weakens them. Thus far, the former path—a recommitment to IHL—seems to be taking shape, as evidenced by the world’s reaction and the persistent calls to hold perpetrators to account.

Precedent Comparison (Kosovo and Other Self-Determination Claims)

From the outset, Russia has attempted to frame its actions in Ukraine as consistent with international precedents or to accuse the West of double standards in its own past interventions. A critical examination of these comparisons, especially the oft-cited Kosovo case, reveals significant differences and highlights how Russia’s reliance on them is largely opportunistic and legally unconvincing.

Kosovo (1999–2008) vs. Crimea/Donbas (2014–2022)

The NATO intervention in Kosovo in 1999 and Kosovo’s subsequent declaration of independence in 2008 form the centerpiece of Russia’s “precedent” arguments. In 1999, NATO forces (without UN authorization) bombed the Federal Republic of Yugoslavia to halt what they described as an impending ethnic cleansing or genocide of Kosovo Albanians by Serbian forces. This was presented as a humanitarian intervention to avert a catastrophe. After the conflict, Kosovo came under UN administration, and in 2008—nearly a decade later—it declared independence, which has since been recognized by around half the world’s countries (mainly Western powers). Importantly, NATO did not annex Kosovo; the intervention’s stated aim was humanitarian, not territorial conquest, and the post-war process involved extensive international oversight (UN, EU) leading to supervised independence.

Russia, at the time, vehemently criticized the Kosovo intervention as an illegal use of force and opposed Kosovo’s unilateral independence as a violation of Serbia’s territorial integrity. Moscow’s stance was that allowing Kosovo to secede without Serbia’s consent would create a dangerous precedent in international law. Indeed, in the 2010 ICJ advisory opinion on Kosovo’s declaration of independence, Russia (along with Serbia) argued against any right of unilateral secession.

Fast forward to the post-Soviet space: Russia paradoxically invokes the “Kosovo precedent” to justify its own actions in places like Georgia (2008) and Ukraine (2014/2022). This is a classic case of political double standards. For example, after Russia fought a brief war with Georgia in 2008, it recognized the breakaway Georgian regions of Abkhazia and South Ossetia as independent states. Vladimir Putin’s government explicitly cited Kosovo’s independence as justification, claiming that if the West carved Kosovo out of Serbia, Russia could do the same for territories that purportedly desired to escape Georgian rule. Yet, prior to that, Russia had never recognized any of the separatist “frozen conflict” regions in its neighborhood, adhering to a principle of territorial integrity—a principle it conveniently discarded when it suited its strategic aims.

The pattern repeated with Ukraine. In 2014, when Russia occupied and annexed Crimea, Putin’s speech to justify the move referenced Kosovo’s earlier secession. He argued that Western countries, by recognizing Kosovo, had set an example that Crimea was following—claiming that Crimea’s Russian-speaking population had an equal right to self-determination. However, that analogy is deeply flawed. In Kosovo, the population had suffered years of repression and a brutal campaign by Serb forces, leading to a humanitarian crisis and UN administration; in Crimea, the population was not under violent threat in 2014—the change in government in Kyiv posed no physical danger to Crimeans. Moreover, Crimea’s March 2014 “referendum” was conducted under the presence of Russian troops, over just a few weeks, and produced a wildly implausible 97% pro-annexation result. It lacked any international monitoring or negotiations—unlike Kosovo, whose status was debated for years in international forums. The UN General Assembly, in response, affirmed that the Crimean referendum had “no validity” and nations have an obligation not to recognize the outcome. In essence, while the West portrayed Kosovo as a sui generis case not governed by clear law, Russia has tried to normalize its own interventions by cherry-picking the Kosovo example—even as it simultaneously insists Kosovo was illegitimate. As one analyst observed, Russia has “reconfigured, reinterpreted, and reframed” legal concepts like sovereignty and self-determination in a self-serving manner, “without the need to establish consistency or inner logic.” Thus Russia cites Kosovo when convenient, even though Russia’s own actions go beyond anything done in Kosovo (notably by outright annexing territory).

In 2022, Putin again evoked Kosovo when he proclaimed the annexation of four Ukrainian regions (Donetsk, Luhansk, Kherson, and Zaporizhzhia) after hastily organized referendums. He openly admonished the West, “Do not forget the Kosovo precedent, my Western friends,” to argue that annexing these regions was exercising the same principle that created independent Kosovo. This argument was widely rejected. Western governments and the UN drew a clear distinction: Kosovo’s case did not involve one country annexing the territory of another, whereas Russia was blatantly attempting to absorb parts of a sovereign state by force. Even countries that were uneasy with Kosovo’s precedent (like many in the Global South) did not accept it as license for violent territorial aggrandizement. In fact, the inconsistency of Russia’s stance has been remarked upon by commentators and other states—Moscow opposes Kosovo’s independence to this day, yet demands that the world accept Crimea’s annexation and the independence (or annexation) of Donbas regions, which Russia itself orchestrated. This undermines any claim of acting on principle; rather, it shows principle being invoked as cover for power politics.

Self-Determination vs. Territorial Integrity: The clash between these principles is at the heart of the Kosovo and Donbas comparisons. International law upholds the right of peoples to self-determination, but outside the colonial context, this is usually understood as a right to internal self-governance, not an automatic right to secede unilaterally. The remedial secession theory—that a group facing severe oppression could lawfully declare independence as a remedy of last resort—remains controversial and not codified. In the Kosovo advisory opinion, the ICJ notably did not endorse a general right of remedial secession; it simply held that Kosovo’s declaration didn’t violate international law because international law is mostly silent on declarations of independence. Russia, in that case, argued that even if remedial secession exists, it did not apply to Kosovo’s relatively less dire situation. It is thus highly disingenuous for Russia to turn around and assert remedial secession for regions in Ukraine where, prior to Russia’s own intervention, residents were not facing anything remotely like the mass atrocities that might warrant secession. As the Völkerrechtsblog put it, even if one were to accept remedial secession doctrine, Russia’s aggression “fails remedial secession standards” on multiple counts: the requisite extreme persecution was absent, the purported popular will was not freely expressed, and the “referendums” were manifestly unfree and engineered. In short, Kosovo’s case cannot legally justify Russia’s actions, and Russia’s selective invocation of it exemplifies a double standard—one that the international community by and large has not bought.

Other Comparisons and Double Standards

Beyond Kosovo, Russia and some sympathetic commentators often point to other instances where Western countries have used force or supported secessionist causes, arguing that a similar logic is playing out in Ukraine. It is important to critically assess these analogies:

• Iraq 2003: The U.S.-led invasion of Iraq, undertaken without Security Council approval and on dubious claims of self-defense (WMDs), is frequently cited by Russia to deflect criticism. Indeed, the Iraq War was widely seen as a violation of the UN Charter, and many legal scholars (and nations) condemned it at the time. However, even if one considers the Iraq War illegal, it does not provide a legal justification for Russia’s invasion of Ukraine. International law is not based on “precedents” of unlawful actions; one state’s violations do not permit another’s. If anything, Iraq 2003 and Ukraine 2022 both illustrate the problem of powerful states bypassing the UN system—they are parallel breaches, not legal validations of each other. Moreover, the geopolitical context differed: the U.S. faced serious reputational costs and global protest over Iraq, whereas in Ukraine’s case, Russia’s action has united most of the world in opposition rather than apathy. Russia’s whataboutism on Iraq underscores a political truth (major powers have flouted the law too) but fails as a legal defense—“tu “quoque” (you did it too) is not recognized in law as justification.
• Georgia 2008 and Others: Russia’s brief war in Georgia in 2008, which it claimed was to protect South Ossetians from Georgian aggression, has similarities to the Ukraine scenario (protection of breakaway regions). But that conflict began when Georgia tried to reassert control over South Ossetia and Russia intervened massively. An EU fact-finding mission later found that while Georgia’s initial attack sparked the war, Russia’s military response went far beyond reasonable protection, and it too violated international law (for instance, by invading parts of Georgia proper). Russia then unilaterally recognized South Ossetia and Abkhazia, again citing humanitarian reasons and self-determination. These actions were met with nearly unanimous non-recognition internationally—the world did not accept Russia’s carve-up of Georgia. The lesson drawn was that unilateral secession backed by force would not gain legitimacy (an outcome reaffirmed now with Ukraine’s regions). Similarly, Russia has supported the breakaway region of Transnistria in Moldova for decades, while Western states have not recognized it. These cases show Russia’s pattern of leveraging separatism to weaken neighboring states under a veneer of legal rhetoric that it does not consistently apply (for example, Moscow harshly suppressed Chechnya’s bid for independence in its own territory, allowing no such self-determination).
• Other Secessionist Movements: Western countries themselves have not supported most secession movements globally. For instance, when parts of Ukraine’s Donbas were held up by Russia as analogous to Kosovo, Western governments retorted that Kosovo was unique and refused to recognize Donetsk/Luhansk. They likewise rejected the 2017 Catalan independence referendum in Spain (calling it unconstitutional under Spanish law) and did not endorse the 2017 Kurdish independence referendum in Iraq. The principle generally upheld is territorial integrity, with rare exceptions. The inconsistency lies more in the NATO-Kosovo case (seen as exceptional) than in Ukraine, where Western responses have aligned with their usual support for maintaining existing borders. However, from the perspective of many in the Global South, there is indeed a perception of double standards: that powerful Western countries invoke international law selectively—criticizing Russia now but having bent rules earlier for themselves or allies. This sentiment was voiced, for example, by the representative of the Democratic Republic of Congo at the UN, who, while supporting Ukraine, lamented the “politics of double standards” and asked why similarly strong action is not taken in other cases of invasion or occupation around the world. Implicitly, this refers to situations like the Israeli–Palestinian conflict or conflicts in Africa that some feel have not received equal global attention or censure.

In evaluating these comparisons, a few points stand out. Legally, each situation occurs in its own context and facts; none provides a legal license for the Ukraine invasion. Politically, however, the legacy of past actions (Kosovo, Iraq, etc.) complicates the narrative—Russia exploits those precedents to claim hypocrisy by the West, while Western leaders insist that Ukraine is a clearer case of wrongful aggression than those prior episodes. The upshot for international law is a challenge: to demonstrate consistency and uphold principle over geopolitics. Despite instances of great-power hypocrisy, the broad coalition defending Ukraine’s sovereignty suggests a reassertion of foundational norms rather than their abandonment. Many states that opposed the Iraq War (including U.S. allies like France and Germany) are equally opposed to Russia’s war in Ukraine, indicating that fidelity to the UN Charter can transcend blocs. Furthermore, Russia’s attempts to mirror Western justifications (e.g., using “R2P” language) show the enduring power of those legal concepts—even violators feel compelled to invoke law, not openly derogate from it. In a paradoxical way, by straining to shoehorn its aggression into legal justifications, Russia has underscored that outright rejection of international law’s authority would leave it completely isolated.

In conclusion, historical precedents like Kosovo do not exonerate Russia’s actions; if anything, Russia’s misuse of those examples highlights the need for clearer rules and more consistent application. The Russia–Ukraine conflict may well become a precedent in its own right—a precedent for how the world responds to blatant aggression in the 21st century. Will it be remembered as a triumph of the international rule of law (with the aggressor held accountable and norms strengthened), or as a failure that emboldened cynical power plays? The answer may depend on the international community’s willingness to confront its own double standards and fortify the legal order against such abuses.

Legal Reform Proposals

The Russia–Ukraine war has exposed various weaknesses and ambiguities in the international legal system. While the existing law clearly prohibits Russia’s actions, the crisis has shown gaps in enforcement and interpretation that, if not addressed, could be exploited by future aggressors. In this section, we propose several realistic and academically grounded legal reforms to bolster the international legal order in light of lessons from this conflict. These proposals focus on (1) United Nations Security Council reform and (2) clearer rules on remedial secession; (3) tighter limits on claims of preemptive self-defense; (4) safeguards against illegitimate referenda in conflict zones; and (5) other relevant measures (such as accountability mechanisms for aggression). Each proposal aims to reduce the chance of a repeat of the Ukraine scenario or at least improve the collective response when international law is breached.

1. United Nations Security Council Reform

Problem Exposed: The UN Security Council, charged with primary responsibility for maintaining international peace and security, was effectively paralyzed by Russia’s veto from the start of this war. As a permanent member (P5) of the Council, Russia was able to block any binding action or resolution condemning its own aggression. This highlights a structural problem: the UN system entrusts global security management to the great powers but provides no effective override when one of those powers is the lawbreaker. The Ukraine war has thus underscored what many have long noted—the veto power can be “a major stumbling block to peace” when misused. During the Cold War, superpower vetos often stymied the Council, and the same dynamic persists, as seen now with Russia (and potentially with others in different contexts). An increasingly ineffectual Security Council undermines the entire collective security framework of the UN.

Reform Ideas: To address this, scholars and statesmen have renewed calls for Security Council reform. One bold proposal is to curtail the absolute veto by introducing a mechanism to override it in atrocity situations. For example, an amendment to the UN Charter could allow a veto to be overridden by a qualified majority vote in the General Assembly or even in the Council itself (minus the vetoing member). A specific idea suggested is a “double majority” override: if two-thirds of UN member states, representing at least two-thirds of the world’s population, vote to override a P5 veto, the veto would not stand. This would effectively empower the broader international community to act when a P5 member abuses its veto to shield flagrant violations of international peace. Such a change would require a charter amendment—a difficult process, since it could be vetoed by the very powers it’s meant to constrain. Yet, proponents argue that the unprecedented unity against Russia’s aggression might galvanize momentum for reform. Even the threat or discussion of removing or suspending Russia’s veto (for example, by reviving the long-dormant Uniting for a peace mechanism or through creative legal interpretation of the Charter) puts pressure on the system to evolve.

In the interim, pragmatic steps short of formal amendment can be taken. One is the political initiative already underway: in April 2022, the General Assembly adopted a resolution requiring the P5 to justify their vetoes in a GA session. This “veto accountability” mechanism at least shines a spotlight on obstructionist vetoes. Additionally, France and Mexico have championed a voluntary P5 agreement to refrain from using the veto in cases of mass atrocities. Over 100 states support this initiative, although Russia (and China, and ironically the United States too) remain cool to it. Still, if enough pressure builds, even voluntary self-restraint could become a norm. For instance, had such a norm been in place, Russia’s lone veto in February 2022 on a resolution deploring its invasion might have been politically costlier or even deterred.

Another aspect of Security Council reform often raised is membership enlargement or regional representation. While expanding the Council (adding new permanent or non-permanent members) is primarily about legitimacy and representation, not directly about the Ukraine scenario, a more representative Council might marginalize abuses of power. For example, if countries from Africa, Latin America, or South Asia (currently underrepresented) had a permanent seat, their perspectives on conflicts and double standards would be more audible. However, without addressing the veto, mere enlargement won’t solve paralysis in the face of a P5 aggressor. Therefore, the core issue is the veto. Some have floated suspending a P5’s veto rights when it is a party to a dispute under Chapter VII action—an interpretation arguably allowed by Article 27(3) of the Charter (which mandates abstention by parties to a dispute in Chapter VI decisions, but not Chapter VII). Extending that logic to Chapter VII (enforcement) could be a way through practice, though it would likely be rejected by the P5 as a group for fear of setting precedents.

Realism and Impact: Admittedly, any structural reform of the Security Council faces steep political hurdles—including the need for the P5 to consent to a diminution of their own privilege. However, the shock of Russia’s actions has reopened this debate. It is not entirely utopian to imagine, for instance, a review conference of the UN Charter where a coalition of states pushes through an override mechanism, especially if one or more P5 are internationally isolated. Even if immediate Charter amendment is unlikely, the normative pressure is important: The more the international community asserts that the veto should not protect atrocity crimes or aggression, the more delegitimized such vetoes become. Over time, this could influence the behavior of the Council (much as the use of veto has declined in frequency since the 1990s except on a few contentious files). In the best case, the Ukraine war could be an impetus—like World War II was for the creation of the UN—to make the Security Council fit for purpose in an era where gross violations cannot be allowed to go unchecked by collective action. A reformed Council or strengthened alternative mechanisms (like the General Assembly’s Uniting for Peace, which was used in this case to make recommendations in lieu of Council action) would greatly enhance the enforcement of international law against aggression.

2. Clarifying Remedial Secession and Self-Determination

Problem Exposed: The ambiguity in international law regarding when, if ever, a subset of a state’s population may unilaterally secede (break away) has been a gray area that Russia exploited rhetorically. Terms like “self-determination” and “remedial secession” were used by Russia to justify recognizing Donetsk, Luhansk, and Crimea as no longer part of Ukraine. The lack of a clear legal standard allowed Russia to pretend it was helping an oppressed people attain independence, even though the situation did not meet any genuine criteria of self-determination struggles recognized historically (such as colonial rule or truly severe persecution). This suggests a need to articulate more clearly the balance between the principle of territorial integrity and any exceptional right to secession.

Reform Ideas: The vast majority of states hold that unilateral secession is not a right under international law (except in decolonization contexts). However, many also acknowledge a theoretical possibility often phrased as, “Where a people is subject to alien subjugation, domination, and exploitation—or faces grave human rights abuses—and where no other remedies exist, secession might be a last resort.” This is the concept of remedial secession. To prevent abuse of this concept (as by Russia’s false claims in Ukraine), the international community could seek to codify guidelines or criteria for remedial secession. For instance, through a General Assembly declaration or an ICJ advisory opinion request, states could enumerate the conditions under which a claim to independent statehood by a region might be considered legitimate. These conditions might include (a) Massive, ongoing human rights violations or humanitarian catastrophes attributable to the state, such as genocide or ethnic cleansing; (b) that all peaceful and internal avenues for redress (such as autonomy arrangements) have been exhausted; (c) that secession is a last resort to preserve the existence of the people; and (d) that the secession is declared by a representative leadership of the people and (crucially) is done with a free and fair expression of popular will (e.g., a referendum) under neutral supervision.

Even if such criteria are met, the preference could still be for negotiated solutions—but if a people meets them and no agreement is forthcoming, international law might in principle accept the outcome. The key would be to emphasize that these situations are extraordinarily rare. By articulating this, the world can more easily call out sham cases. In Ukraine’s case, did the people of Donetsk or Crimea face destruction or genocide by Kyiv’s government? Clearly not—as international observers like the OSCE confirmed. Were they denied any and all forms of participation or autonomy? No—before Russia’s interference, Russian-speaking Ukrainians had political representation and linguistic/cultural rights (albeit there were policy disputes). Was secession a last resort after peaceful options failed? No—rather, Russia fomented a conflict. And was there a genuine democratic choice to secede? Absolutely not—the so-called referenda were conducted under foreign military occupation with predetermined outcomes. Thus, by any reasonable criteria, the secessions were not remedial but fabricated.

A GA resolution could spell this out generically, which would bolster the argument against recognition of territories seized under false claims of self-determination. It could also reaffirm that outside military intervention is not justified by secessionist invitations unless those invitations come from a bona fide people entitled to remedial secession—a very high bar. The ICJ, if asked, might clarify (as it hinted in the Kosovo opinion) that while international law doesn’t generally grant a right to breakaway regions, it also doesn’t license other states to use force to “help” such regions, except possibly in a true decolonization context.

Realism and Impact: Many states are cautious about formalizing remedial secession because they fear encouraging separatism (most countries have their own restive regions or minorities). So any codification would likely reaffirm territorial integrity as the norm and frame remedial secession as an extremely limited exception, if at all. Even that could be controversial—some major states (Russia included, ironically) have opposed the concept outright. Nonetheless, an authoritative statement from the international community could help pull the rug out from under cynical invocations of self-determination. It would make it easier to achieve consensus that, say, Crimea’s annexation is void because the preconditions for a lawful secession did not exist and because the process violated core principles (voluntariness, absence of force). Over time, this clarity could deter aggressors from using the “independence” excuse. It might also help genuine causes: if ever there is another Kosovo-like situation, having criteria could either dissuade unilateral action or, conversely, provide a legal roadmap for when the world should step in to carve out a new state (as a last humanitarian resort). In sum, clarifying the law on secession and self-determination would close a loophole that Russia tried to exploit, reinforcing that territorial integrity is inviolable except in the most exceptional circumstances, which were not present in Ukraine.

3. Limiting Claims of Preemptive Self-Defense

Problem Exposed: Another ambiguity highlighted by the conflict is the concept of anticipatory or preemptive self-defense. The UN Charter says self-defense is triggered “if an armed attack occurs.” Yet, states have debated whether they may lawfully strike first if an armed attack is imminent (the Caroline doctrine from the 19th century implies yes, if imminence is strict) or, even more controversially, to neutralize a non-imminent but growing threat (“preventive” self-defense, which has no broad support). Russia essentially claimed a preventive self-defense in Ukraine, arguing that NATO’s expansion and Western military support to Ukraine posed a future threat that had to be addressed militarily. This rationale is very similar to the U.S. Bush Administration’s 2002 doctrine that was used to justify the Iraq War (which posited hitting emerging threats before they materialize). The global reaction to Russia’s claim—rejection and condemnation—suggests that the law as understood by most states does not accept such far-reaching self-defense. However, because a few powerful states have flirted with expansive interpretations, it remains an area of potential exploitation.

Reform Ideas: The international community could take steps to re-emphasize and clarify the limits of the self-defense doctrine. One way would be through an updated UN General Assembly resolution on the Use of Force, effectively a 21st-century reaffirmation of the principles of the Charter. (The last major consensus statement was the 1974 Definition of Aggression, and before that, the 1970 Friendly Relations Declaration.) Such a resolution could explicitly state that (a) self-defense is permitted only in response to an armed attack or, at most, an imminent armed attack. (b) Preventive war—the use of force in response to threats that are generalized or potential and not immediately about to occur—is not lawful under international law. (c) Any claim of anticipatory self-defense must meet high standards of evidence and imminence, consistent with the Caroline test (necessity and immediacy).

In essence, this would put the international community on record rejecting the notion of “preemptive strikes” absent clear imminence. It could also incorporate the requirement (already implicit in Article 51) that even when acting in self-defense, a state must report measures taken to the Security Council and work toward collective security. Russia did report its claims to the Council, but the claims were spurious. Perhaps states could agree on language that false or unsubstantiated claims of self-defense are themselves grave violations (an abuse of Article 51).

Another mechanism is through jurisprudence: if the ICJ were to handle a contentious case on the use of force (for example, Ukraine has cases against Russia in other courts; if any came to the ICJ on the use of force, or perhaps in an advisory capacity), it could clarify the law. The ICJ in past cases (e.g., the 1986 Nicaragua case) held that arming rebels or anticipating attacks doesn’t justify force unless an armed attack has actually occurred or is instantly pending. Reiterating these points in a new judgment could further solidify them. Additionally, international scholarly bodies (like the International Law Commission or the Institute of International Law) could produce draft articles or resolutions on self-defense, consolidating the orthodox view.

Realism and Impact: Many countries—especially those in the Non-Aligned Movement—would likely favor a GA resolution restricting preemptive war, since they fear being targets of powerful states’ “anticipatory” use of force. Even Western states that once entertained broader self-defense (like the U.S. in 2003) might sign on now, given the object lesson of Russia’s abuse and the change in administrations/policies since the early 2000s. In fact, after the Iraq war, the world saw a recommitment to the Charter language (the 2005 World Summit outcome document explicitly stated that the Charter is sufficient to address threats, implying no new exceptions like preemption are acceptable). So building on that consensus is feasible.

A clear reaffirmation would constrain not only Russia but any state considering doing something similar. For instance, it would make it harder for a nuclear-armed state to rationalize attacking a neighbor over a hypothetical future threat (one thinks of potential scenarios like a conflict over disputed territory where a state might claim it feared an attack and struck first—these would be less tenable legally). It also aligns with efforts to strengthen peace: diplomacy and deterrence should handle emerging threats, not unilateral force. If the norm against preventive war is strengthened, states will know they must present concrete evidence of an imminent attack if they want any legal sympathy for striking first. Otherwise, they risk the kind of isolation Russia is experiencing. In summary, narrowing the scope of self-defense to its classic meaning fortifies the collective security system because it channels major threats to the Security Council and away from unilateral war-making. The Ukraine experience provides a persuasive impetus for the world to draw that line clearly.

4. Safeguards Against Abusive Referenda and Annexations

Problem Exposed: The Ukraine conflict has seen the brazen use of referenda as a weapon—essentially, the occupying power (Russia) staging votes in conquered areas to claim legal title to them. This tactic, while not new in history, poses a challenge to international law: how to treat the results of such referendums and how to prevent their abusive use. In 2014, Russia organized a referendum in Crimea (in violation of Ukraine’s constitution and amid an occupying military presence) and then annexed the territory. In 2022, it repeated the strategy in parts of Donetsk, Luhansk, Kherson, and Zaporizhzhia. The international response was to refuse recognition of these actions—as noted, the UN General Assembly declared the 2022 referenda and annexations null and void. However, this was reactive. There is no explicit treaty rule saying, “You can’t annex territory via a fake referendum”—it”’s inferred from the broader principles of ex injuria jus non oritur (illegal acts cannot create law) and the unlawfulness of acquiring territory by force. Making these implications more explicit could deter future attempts to cloak aggression in the guise of “popular will.”

Reform Ideas: One approach is to develop international standards for secessionist or annexation-related referenda. For example, the Venice Commission (an advisory body of the Council of Europe) has a Code of Good Practice on Referendums, which, while not legally binding, provides guidelines for how any referendum should be conducted (free campaigning, international observation, etc.). Building on such efforts, states could agree (perhaps in the UN or another multilateral forum) on a set of criteria that must be met for a referendum on sovereignty to be considered valid internationally. These criteria might include: (a) The referendum is conducted pursuant to a legitimate domestic legal process or an international agreement (i.e. not unilaterally by a local faction or an occupying force); (b) It takes place in a climate free of intimidation, with independent observers verifying the integrity of the vote; (c) The population eligible to vote is clearly defined and stable (no mass importation or displacement of people to skew demographics – something Russia was accused of doing via deportations and migration in occupied areas); (d) The question posed is clear and the options are fair; (e) Ideally, the parent state and the aspiring entity negotiate the terms (as was attempted, for example, in Sudan leading up to South Sudan’s 2011 independence referendum, which was internationally supervised and agreed by Khartoum).

Additionally, the international community could resolve that no territorial acquisition resulting from aggression or illegal use of force will ever be recognized—a doctrine already well-established since the Stimson Doctrine and now part of customary law. Reiterating this in the context of referenda would put potential aggressors on notice that running a sham vote will not confer even a veneer of legitimacy. The collective non-recognition policy is crucial: it delegitimizes gains from aggression. In the Ukraine case, this policy has largely held (virtually no state recognizes Crimea as part of Russia, nor the 2022 annexations).

To formalize this, states could consider drafting a treaty or declaration on unconstitutional changes of territory, akin to how there are protocols against unconstitutional changes of government. For instance, an agreement that states will sanction and diplomatically isolate any government that attempts annexation via forced referendum and that they will support the victim state’s sovereignty in all fora, denying the aggressor the fruits of its action. This could perhaps be incorporated into the Definition of Aggression: an annexation following an illegal referendum could be explicitly listed as an act of aggression (though arguably it already is encompassed by existing definitions).

On a more technical level, involving election-monitoring bodies (like the UN Electoral Assistance Division or the OSCE) whenever there is a self-determination plebiscite could become a norm. If a group truly wants to secede and claims legitimacy, they should invite international monitors to verify their referendum. If they refuse or if monitors report irregularities, that should speak volumes. In Donetsk and Luhansk in 2014 and 2022, no credible monitors were present—which by itself signaled the lack of legitimacy.

Realism and Impact: Democracies and rule-of-law states would likely endorse guidelines for valid referenda, as it aligns with principles of democratic expression. Authoritarian states might be wary, though interestingly even China (with its own secession concerns regarding Taiwan, Tibet, etc.) might favor a strong territorial integrity stance that delegitimizes unauthorized referenda. So there could be broad support for a statement like “Any referendum conducted under foreign occupation or during an ongoing conflict is presumptively invalid.” Such a rule doesn’t stop a determined aggressor from holding a sham vote, but it helps unify others to reject it. It also helps counter the information war: Russia tried to use the spectacle of “voting” to claim high-minded motives. Clear international criteria strip away that facade—everyone can say, “This process violated every basic norm of a legitimate referendum; therefore, we reject its result.”

In the long run, establishing these safeguards contributes to a more stable world by reinforcing that borders cannot be changed by force masquerading as self-determination. Genuine self-determination movements (like decolonization cases or agreed separations) typically welcome oversight and legitimacy; illegitimate ones do not. By institutionalizing this difference, the world will be better equipped to handle crises where a region’s status is contested. As an ancillary benefit, it may encourage states to address minority grievances internally (through autonomy or power-sharing) since they know a unilateral secession vote won’t fly unless they egregiously oppress that minority. Thus, it incentivizes better governance and conflict prevention.

5. Other Reforms and Considerations

Finally, the Ukraine conflict has brought to the fore additional legal reform areas that merit attention:

• Accountability for Aggression: As noted, the current international criminal justice system has a gap when it comes to the crime of aggression if the perpetrator is not party to the ICC or is protected by veto. A major reform proposal is to establish a Special Tribunal for the Crime of Aggression against Ukraine via an agreement between the UN (or a group of states) and Ukraine. This tribunal would prosecute Russian leaders for the initial act of aggression—a crime defined in the Rome Statute amendments and in UN GA Resolution 3314 but not prosecutable by the ICC here due to jurisdiction limits. The creation of such a tribunal (perhaps modeled on past tribunals like Nuremberg or the more recent special court for Sierra Leone) would reinforce the norm that starting an illegal war is the gravest war crime of all and that even heads of state can be held accountable. Over time, this could feed into a reform of the ICC itself—persuading more states to accept the ICC’s jurisdiction over aggression by acceding to the Kampala Amendments so that in the future, aggression by any state could be tried without needing Security Council approval. The political challenge is enormous—Russia and some others would cry victor’s justice—but if done through a broad coalition, it sets a powerful precedent. Even a trial in absentia or an indictment is symbolically significant (as the ICC’s Putin warrant has shown).
• Reaffirming the Prohibition on Acquiring Territory by Force: While this is already a bedrock norm (part of jus cogens), the war might spur a new global commitment akin to the Helsinki Final Act (1975) principles, which included inviolability of frontiers. Perhaps a new conference or treaty could get states, including Russia’s allies, to recommit to not recognizing changes of borders achieved by war. This could tie into the referendum safeguards mentioned above.
• Enhancing the Role of the UN General Assembly: In cases of Council deadlock, the GA has stepped in (using “Uniting for Peace”) to make recommendations and marshal global action. We have seen this with Ukraine—multiple emergency special sessions and GA resolutions marshaling moral authority. A reform idea is to further empower the GA in peace and security, maybe not to authorize force (since that would require a charter amendment) but to take on some deliberative and investigatory functions. For example, the GA could establish a standing Fact-finding mechanism that rapidly investigates claims used to justify war (such as Russia’s claims of genocide). Had such a neutral body been dispatched to Donbas pre-invasion, it could have reported back that no genocide was occurring, undercutting that pretext. Strengthening the UN’s capacity to verify facts can help prevent disinformation-driven conflicts.
• Clarifying Humanitarian Intervention/R2P: Russia’s abuse of R2P rhetoric (while committing the very crimes R2P is meant to stop) has been galling. The international community might use this moment to clarify that unilateral humanitarian intervention remains unlawful—R2P should be exercised collectively through the UN system. Some states, fearing misuse of R2P, have wanted a firmer line that it’s not a standalone legal doctrine allowing force. An official statement to that effect could be made. Alternatively, some have proposed a treaty on “Responsibility While Protecting” (an idea floated by Brazil) to ensure interventions, when they happen, are monitored and limited. While the appetite for new exceptions is low (and rightly so), improving how real humanitarian crises are handled—so that genuine cases (like Rwanda 1994 or, theoretically, a future mass atrocity) don’t go unanswered—is part of the equation. If the Security Council were reformed to not allow vetoes in such cases, that would solve much of it; absent that, frameworks to ensure any humanitarian use of force is genuinely multilateral and evidence-based could be worked on.
• Addressing New Forms of Warfare: The Ukraine war has also been a testing ground for cyber operations, disinformation campaigns, economic coercion (energy supply cuts), and nuclear saber-rattling by the aggressor. Legal development is needed in each of these areas. For instance, working toward international agreements on cyber warfare (what constitutes a use of force or armed attack in cyberspace?) would reduce ambiguity. Russia conducted cyberattacks against Ukrainian infrastructure even before the kinetic invasion; how should such acts be classified legally? Similarly, Russia’s thinly veiled nuclear threats broke the taboo against nuclear coercion. The international legal regime could be strengthened by declarative statements (e.g., a global reaffirmation that threatening nuclear use in support of aggression is unacceptable and violates international law, perhaps via the UN or the NPT review). process). While these issues go beyond classical jus ad bellum/in bello, modern conflict blurs these lines, and the law must adapt accordingly.

In proposing these reforms, it is understood that international law often moves slowly and incrementally. However, major conflicts have historically been catalysts for legal evolution. The horrors of World War I led to the Geneva Protocol on chemical weapons and the League of Nations; World War II’s devastation led to the United Nations Charter and the human rights revolution; the Balkan wars of the 1990s spurred the creation of ad hoc tribunals and eventually the ICC. The Ukraine war, being such a defining confrontation in the 21st century, may likewise serve as an inflection point. It has reminded the world of both the frailties and the necessity of the international legal order. By learning from it and implementing reforms like those above, the global community can hope to reduce the likelihood of future wars of aggression and ensure that if they are attempted, they will be met with a stronger, more unified legal and institutional response.

Conclusion

The Russia–Ukraine conflict is a stark test of the international legal system’s resilience. This comprehensive assessment has examined how the war implicates the core tenets of international law—from the jus ad bellum prohibition on aggression to the jus in bello rules of humane conduct to the consistency (or lack thereof) in applying legal principles across different conflicts. The findings are both sobering and instructive.

At its heart, Russia’s invasion of Ukraine represents a grievous violation of the UN Charter’s most fundamental rule: the ban on the use of force for territorial conquest or coercion. No amount of legal rhetoric can obscure that reality. The justifications offered by Moscow have been thoroughly unconvincing on legal grounds and, indeed, unprecedented in their audacity. Claims of self-defense ring hollow when no attack occurred or was imminent. Appeals to stopping “genocide” or protecting human rights collapse under the evidence that no such genocide was happening—on the contrary, the intervention itself unleashed massive human rights abuses. The invocation of self-determination and remedial secession is exposed as cynical when one recalls that Russia previously championed territorial integrity (and denies those same rights to regions within its own federation). In the final analysis, Russia’s action is a textbook case of aggression, as virtually the entire international community has recognized. This near-unity in diagnosis is a heartening sign that, for all the political rifts in the world, certain legal norms remain clear and universal: one state cannot simply invade and take over another.

During the conflict, international humanitarian law has sadly been violated on a massive scale, but it has also proved its enduring relevance. The extensive documentation of attacks on civilians, torture, sexual violence, and forcible deportations in Ukraine has spurred an unprecedented global effort to enforce IHL. Never before has a major power’s military conduct been so scrutinized in real time. Investigations by the UN, ICC, and civil society have ensured that the atrocities do not remain hidden or denied. The issuance of an ICC arrest warrant against a sitting head of state (President Putin) for war crimes is a watershed moment for accountability, even if actual arrest is for now unlikely. It signals that the age of impunity for leaders who commit egregious crimes is drawing to a close. For Ukraine and its people, justice may be slow and partial, but the framework to achieve it is in motion—from war crimes trials to discussions of reparations and reconstruction financed by frozen assets of the aggressor. This conflict may thus rejuvenate the enforcement of IHL, reinforcing the idea that war crimes will be documented and punished, if not immediately, then eventually. Such a message is crucial to deterring future violations and upholding our shared humanity in war.

The war has also forced a confrontation with the double standards and inconsistencies that have long plagued international law. Critics around the world have pointed out that the swift and forceful response to Ukraine’s plight contrasts with comparatively tepid responses to other violations (be it Palestine, Syria, Yemen, or past U.S.-led interventions). These observations are valid to an extent and underscore that global justice is still often selective. However, rather than using this as an excuse to dilute the response in Ukraine, the better lesson is to elevate responses elsewhere to the same principled level. If the world can unite to reject aggression and uphold law in this case, why not in all cases? The credibility of international law hinges on its consistent application. One positive development is that many countries in the “Global South” that are skeptical of Western geopolitics nonetheless supported key UN resolutions defending Ukraine’s sovereignty—not out of love for one side or the other, but because the principle at stake (that borders cannot be changed by force) is of universal importance, especially to smaller and medium states. Moving forward, closing the gap between principle and practice—by addressing conflicts with the same zeal for legality, regardless of who the perpetrator is, would strengthen the international legal order for everyone’s benefit.

The conflict has illuminated certain grey zones (like those around secession or preemptive defense), and it has spotlighted institutional failings (like the Security Council veto issue). But it has also reaffirmed some fundamental truths of the international system. One is that international law still matters—it shapes global narratives, it influences states’ behavior (even Russia felt compelled to justify itself legally), and it provides mechanisms (courts, investigations, diplomatic processes) to respond to crises. Another truth is that aggression, while temptingly effective in the short term, tends to galvanize a broad counter-coalition. In today’s interconnected world, an aggressor faces sanctions, isolation, and legal jeopardy that did not exist in ages past. This is progress attributable to international law and institutions. Russia’s war was intended to subjugate Ukraine, but it ended up reinvigorating NATO, unifying the EU, and prompting neutral states to take moral stands—outcomes that flow from a shared recognition of unlawful wrong. In a sense, the war has become a struggle not just about Ukraine’s territory but about the future of international norms. Ukraine’s staunch resistance, legally premised on self-defense and the inherent right to sovereignty, has become a rallying point for the idea that the international rule of law must be upheld, lest we revert to a might-makes-right world.

From an academic and policy perspective, this conflict offers many lessons and has already triggered proposals (some of which we outlined) to reform the system. Implementing reforms like UN Security Council changes, clearer definitions for contested principles, and improved accountability mechanisms will be challenging, but the very fact they are on the agenda is a sign of the system trying to self-correct. History shows that international law evolves through crises—and often because of the determined efforts of far-sighted individuals and coalitions in the aftermath. It is incumbent on legal scholars, diplomats, and leaders to seize this moment to advocate changes that can prevent or mitigate the next crisis.

In conclusion, the Russia–Ukraine war has been a tragedy of immense proportions for those directly affected, but it has also been a clarion call for the international community. It has laid bare the stark choice we face: recommit to the rule of law and collective security, or slide into a new era of disorder and conflict. The response so far—overwhelming condemnation of aggression, support for Ukraine’s defense, and moves toward justice—suggests that the international community, imperfect as it is, has chosen to stand on the side of the law. The road ahead is long: the war is not over, justice is not fully served, and reforms are not yet realized. But if the solidarity and clarity of principle witnessed in this crisis can be sustained and translated into concrete legal and institutional advances, the legacy of this dark chapter may ultimately be a more enlightened international order. Such an outcome would honor the sacrifices of those who suffered and would reassert the fundamental promise of international law: to save succeeding generations from the scourge of war and to maintain a world where right, not might, prevails.

Sources:

• United Nations Charter, Article 2(4) and 51; U.N. General Assembly Emergency Special Session Resolutions ES-11/1 (2 Mar 2022) & ES-11/4 (12 Oct 2022) condemning the invasion and annexation.
• Lieber Institute, West Point: Analysis of Russia’s jus ad bellum claims, noting Russia’s letter invoking Article 51 and the lack of any lawful basis. Also discussion of anticipatory self-defense and the Caroline criteria.
• Völkerrechtsblog: “Self-Determination as Faux Remedial Secession in Russia’s Annexation Policies” explains how Russia’s assertions of genocide and secession in Donbas fail legal tests (OSCE found no genocide; even Russia argued at the ICJ that remedial secession is only for extreme cases). Notes UN GA declaring Russia’s referenda invalid.
• LSE IDEAS Strategic Update (July 2022): “The ‘Kosovo Precedent’: Russia’s Justification of Military Interventions” details how Russia simultaneously condemns Kosovo’s independence but invokes it to justify actions in Georgia and Ukraine. Highlights Russia’s inconsistent manipulation of international legal norms.
• Reports of the Independent International Commission of Inquiry on Ukraine document numerous war crimes by Russian forces, including torture, summary executions, rape, and deportation of children.
• Amnesty International and other NGOs’ reports confirm deliberate Russian attacks on civilians and civilian infrastructure amounting to war crimes. Emphasize that Russia’s war of aggression has caused overwhelming civilian harm.
• International Criminal Court press release (17 March 2023)—announced arrest warrants for Vladimir Putin and Maria Lvova-Belova for the war crime of unlawful deportation of Ukrainian children, holding leaders individually responsible under international criminal law.
• Reuters, AP, and Al Jazeera news reports on UN votes provide data on global reactions (e.g., 143–5 vote declaring annexations illegal) and capture sentiments about double standards.
• Brookings Institution/Project Syndicate Op-Ed (Derviş & Ocampo, March 2022)—argues that the Ukraine war shows the need for UN Security Council reform, proposing a mechanism to override P5 vetoes by a supermajority of members.
• Prior international legal precedents: ICJ Advisory Opinion on Kosovo (2010); ICJ Order in Ukraine v. Russia (Genocide Convention) (16 March 2022) noting lack of evidence of genocide; ICTY jurisprudence on humanitarian intervention; and General Assembly Resolution 3314 (Definition of Aggression). These form the legal context against which the Russia–Ukraine conflict is assessed and future reforms are contemplated.