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International Law on the Battlefield: Lessons for Ukraine and the World


Since February 24, 2022, when Russia initiated a full-scale invasion, Ukraine has made international law a central component of its war strategy. However, last week, the International Court of Justice dealt Ukraine's legal efforts two significant setbacks in a pair of disappointing rulings. Although Ukraine did not lose entirely in both cases, the victories were so minor that a discerning observer described the outcomes as a "huge loss for Ukraine" and a "major disappointment in its 'lawfare' efforts against Russia."


Can the decisions made in Ukraine's favor signal the boundaries of its strategy to prioritize international law in its war efforts? How should the 32 countries that supported Ukraine respond? Furthermore, do these unremarkable decisions indicate that the International Court of Justice is reconsidering its involvement in highly politicized issues, particularly after the significant ruling on preliminary measures requested by South Africa against Israel for alleged violations of the Genocide Convention?


Initially, let's take a moment to examine the two cases in question.


The first legal action, launched by Ukraine in 2017, targeted Russia on two grounds. Firstly, it accused Russia of backing Russian separatist groups in eastern Ukraine, providing them with weapons and training, and thereby violating the International Convention for the Suppression of the Financing of Terrorism (ICSFT) of 1999. Additionally, it alleged that Russia had failed to investigate, prosecute, or extradite those involved in financing terrorism on its own territory. Secondly, it claimed that Russian authorities in Crimea were violating the International Convention on the Elimination of All Forms of Racial Discrimination (CERD) by discriminating against various ethnic minority groups, such as by restricting Ukrainian language education.


The Court concluded that Russia violated its obligations by failing to investigate alleged offenses, as outlined in the ICFST, but dismissed all of Ukraine's other claims under the convention. Additionally, the Court found that Russia's implementation of its educational system in Crimea after 2014, specifically in regards to school education in the Ukrainian language, violated the CERD. However, the Court rejected all other claims under the convention due to insufficient evidence or other reasons. In summary, the Court granted Ukraine a small victory under both treaties, but most of Ukraine's significant claims were dismissed.

The second situation, which has received far more attention, was initiated by Ukraine against Russia shortly after Russia’s large-scale invasion of Ukraine in February 2022. In this case, Ukraine utilized a very clever legal strategy. As there is no international court with jurisdiction over the violation of the UN Charter committed by Russia when it invaded Ukraine, or over the crime of aggression committed by Russian leaders in Ukraine, Ukraine instead resorted to the dispute resolution provision in the Genocide Convention to bring Russia before the court. In a clever twist, Ukraine used Russia's own disinformation against it, arguing that Russia's false claims that Ukraine was engaging in genocide against members of the Russian ethnic minority in eastern Ukraine, which it had used to justify its unlawful acts of aggression, constituted a "dispute" under the Genocide Convention that the Court should resolve. The Court agreed, and in its March 2022 order on provisional measures, it decided that Ukraine's claims were plausible and ordered Russia to "immediately suspend the military operations that it commenced on 24 February 2022 in the territory of Ukraine" - an order that Russia entirely and predictably ignored.


Ukraine's impressive victory on provisional measures had led some to anticipate a similar success at later stages of the proceedings. However, the decision on preliminary objections last week fell short of expectations. While Ukraine's innovative approach, which garnered the support of 32 intervening states, was deemed too clever by half, the court did not completely dismiss the case. Instead, it decided to examine whether there is any credible evidence suggesting that Ukraine is responsible for committing genocide in the Donetsk and Luhansk oblasts of Ukraine, in violation of the Genocide Convention. This outcome is somewhat bittersweet for Ukraine, as the focus of the arguments on the merits will now shift to Ukraine's conduct rather than Russia's. Nonetheless, the court's decision allows it to scrutinize a crucial justification that Russia has offered for its military campaign. Anton Korynevych, the leader of Ukraine's legal team, emphasized the importance of the court's ruling, stating that "It is crucial that the court will determine that Ukraine is not responsible for the mythical genocide that the Russian Federation falsely alleged Ukraine has committed."


Ukraine may have an opportunity to address Russia's violation of the provisional measures order, which was issued by the Court to prevent and punish alleged genocide in the Donbas region. The Court recognized that Russia's actions were taken with the stated purpose of preventing and punishing genocide allegedly committed in the Donbas region, and this gives Ukraine a legal interest under the Genocide Convention to dispute whether genocide was committed. Ukraine may attempt to raise the issue of Russia's unlawful invasion at the merits stage by arguing that Russia violated the provisional measures order, but it is unclear whether the Court will accept this argument since it has previously declined to reach the issue for jurisdictional reasons. The mood among Ukrainian supporters has been generally downcast as a result of these developments.


The Limits of International Law?


Does the fact that these twin disappointments have occurred suggest that Ukraine's decision to prioritize international law in its war efforts was misguided?

The brief response is negative. Ukraine's success against a considerably better-equipped and more potent adversary is primarily attributed to its ability to convince much of the international community that it is defending itself against an unlawful aggressor who is disregarding the fundamental principles of the global legal framework. Although the Court ruled against Ukraine's most forceful assertions in the genocide case, it underlined the significance of adhering to international law in its closing remarks.

The Court reiterated, as it has done previously, the crucial distinction between the acceptance of the Court's jurisdiction by states and the adherence to international law by those states. Regardless of whether states have consented to the Court's jurisdiction, they are obligated to fulfill their obligations under the United Nations Charter and other international legal norms. States remain accountable for actions that contravene international law, irrespective of their consent to the Court's jurisdiction.

This serves as a not-so-subtle message to Russia that, although the Court may not have been inclined to extend its reach to address the issues raised by Ukraine, Russia cannot evade accountability. The rule of law applies irrespective of the Court's jurisdiction.

Russia has incurred significant repercussions for its breaches of international law during this conflict, and these consequences will persist. Perhaps more significant than the ICJ's recent decisions is the European Union's decision on February 1 to approve a 50 billion euro support package over four years. As President Ursula von der Leyen stated while announcing the deal, "These EUR 50 billion for four years... send a very strong message to Putin, just ahead of the second anniversary of his brutal invasion."

This underscores how countries supporting Ukraine can best aid its fight against Russia's unlawful war: by maintaining a dual strategy of imposing sanctions on Russia and providing financial and military assistance to Ukraine. This approach will make a tangible difference in the conflict.


What implications do these developments have for the Court?


Some may question whether these unremarkable rulings suggest that the International Court of Justice is reconsidering its involvement in highly politicized situations. The contrast between last week's decisions regarding Ukraine and the decision on preliminary measures in the South Africa v. Israel case is stark. Is the Court becoming hesitant?

These decisions were likely finalized well before last week, so the international reaction to its decision in the South Africa v. Israel case likely had no bearing on the outcome of Ukraine's cases before the Court. However, there may still be a connection between these cases.

In the South Africa v. Israel case, the Court's determination that South Africa presented a credible case of Israel violating the Genocide Convention garnered global attention. It placed the Court at the center of a deeply charged political, legal, and military standoff. Without police or military support to enforce its decisions, the Court must preserve its credibility, especially when rendering decisions involving Permanent Five Security Council members with veto power over Council decisions, including Russia and the United States. The only formal mechanism for enforcing Court decisions under the ICJ Statute is referral to the Security Council. However, if a state subject to the decision or a close ally holds a permanent Council seat, the likelihood of any resolution enforcing the decision is nil.

Therefore, the Court must exercise caution when issuing such opinions. There may still be reasons to do so, but the Court is likely to hesitate when contemplating stretching its jurisdiction to issue a decision it knows will be disregarded. Ukraine's cases against Russia demanded precisely that. While the theories presented were plausible - as indicated by the Court's favorable responses to applications for provisional measures in both cases - Ukraine asked the Court to venture into legally uncertain territory, especially in the second case. Moreover, it was unlikely that the opinion would have any tangible impact on the ground. Russia had made it clear it would ignore any orders from the Court, and states likely to condemn it had already done so numerous times for unlawful behavior.

Furthermore, a declaration of illegality would be redundant. Few dispute that Russia is violating international law by waging its aggressive war in Ukraine. Over 140 states have repeatedly condemned the war in the General Assembly, beginning with a March 2022 Resolution in which over 140 states demanded that Russia immediately cease its use of force against Ukraine. True, they have not condemned precisely the same violations, but these cases were, after all, argued through treaties not specifically designed to address the fundamental illegality of Ukraine's complaints - the war itself. Unrestricted by the jurisdictional boundaries of the courts, states worldwide have not only denounced Russia's illegal aggression but have also implemented unprecedented sanctions against Russia in response. While a favorable decision by the Court would have been gratifying, it would have been disregarded by Moscow and likely would not have changed much on the ground. Such a judgment may have helped maintain global support for Ukraine, but this support should continue regardless. Therefore, it is perhaps unsurprising that the Court ruled as it did.

The case brought by South Africa against Israel may differ. It is possible that here, too, the Court will proceed cautiously in later stages of the case. Nevertheless, there is reason to believe that South Africa's case may have a different outcome: The Court's decision can have an impact. Despite Israel's leaders publicly denouncing the Court's order, the decision has increased pressure on Israel and its allies, including the United States, to take measures to ensure that Israel respects the fundamental rights and dignity of civilians in Gaza. The United States' adherence to the rule of law makes it difficult to ignore a ruling by the Court that Israel is violating the Genocide Convention. There is also growing political pressure on President Joe Biden to call for a ceasefire in Gaza. Similar dynamics are at play in other states supporting Israel. Litigation is ongoing in the Netherlands, where human rights groups are seeking to halt the Dutch government's export of F-35 fighter jet parts to Israel, arguing that such exports could make the Netherlands complicit in war crimes. Similar litigation is pending in the United Kingdom. If the ICJ concludes, while the conflict is ongoing, that Israel is violating the Genocide Convention, we can expect a surge in similar cases. Thus, even if Israel is determined to ignore a ruling by the Court and the U.S. is ready to block Security Council enforcement, the decision is likely to have an impact if delivered in a timely manner.

How will the Court proceed in the face of these fundamental challenges to the international legal order of which it is a part? Last week's decisions suggest that the judges will continue purposefully but cautiously. As Mariano-Florentino (Tino) Cuéllar and I noted after the Court issued its order on preliminary measures in South Africa's case against Israel, "Because tribunals exist in an unforgiving and difficult political environment, even the most principled among them often have little choice but to consider the practical aspects of their potential decisions.

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