Article: Stanford’s Allen Weiner on Russia’s Invasion of Ukraine and the Laws of War

On February 24, 2022, Russian troops invaded Ukraine, embarking on an unprovoked military aggression against an independent European country—sparking an international outcry, with countries rallying to defend Ukraine in what many describe as the biggest threat to peace and security in Europe since the end of the Cold War.

The human and financial costs have been steep, with approximately 7,000 of innocent civilians in Ukraine dead and 11,000 more injured—and millions more displaced and now living as refugees. Meanwhile, tens of thousands of soldiers have died on both sides. One year on, Ukraine has suffered tremendous losses—buildings, roads, and infrastructure destroyed, and the cost of the war escalating.

Here, Allen Weiner, an international legal scholar with expertise on international security matters, discusses the law governing the use of force, the limitations of the UN to rein in member nations, NATO support for Ukraine, the prospects of war crimes prosecutions, how this historic conflict might end, and more.

What does Russia’s invasion of Ukraine mean in terms of international law? Did Russia violate the UN charter?

It’s always interesting to teach complex, difficult, real-world questions. But if this were an international law class, I would say that Russia’s invasion of Ukraine would not be a very challenging exam question for my students because it is a quite blatant violation of Article 2(4) of the UN charter, which provides that states are not allowed to use force in their international relations. There’s a clear prohibition on the use of force under international law in the UN charter.

There are only two exceptions. One exception is self-defense, and the other exception is the use of force that is authorized pursuant to the collective security powers of the Security Council acting under Chapter VII. Neither of those is present here. There are also some other more contentious or more disputed theories under which states can claim use force under international law. But none of those would apply here, either.

What argument did the Russians use to justify the invasion?

Flags of Ukraine and Soviet union


The Russians have offered two main justifications for the use of force. One is that they somehow perceive that they were threatened by Ukraine because Ukraine might at some point join NATO and could then conceivably have nuclear weapons stationed on its territory. But the right of self-defense is available when a state has sustained an armed attack. Even if there is a right of anticipatory self-defense, which is debated, a state could use force only to ward off an imminent attack, not a threat that Ukraine some years down the road might join NATO. That’s clearly not what the right of anticipatory self-defense contemplates.

The other defense or justification the Russians have offered is that they were protecting co-ethnics, i.e., ethnic Russians in Ukraine, from genocide. There are big debates about whether states can use force to protect their nationals in a foreign country, or whether they can more generally use force to halt humanitarian abuses that are taking place in another country. But we don’t have to dig too deeply into the validity of these legal theories because there seems to simply be no factual support for the claim that ethnic Russians were being subjected to atrocities by the Ukrainian government—it simply isn’t true. And so, whether there could be a legal basis for it, if it were true, seems immaterial.

And has the UN done enough to rebuke Russia?

The UN has done really all it can, under these circumstances. After the invasion of Ukraine, the matter was immediately brought to the Security Council. The way that the Security Council is designed, the five permanent members— the United States, Russia, China, France, and the United Kingdom—have the ability to block the Security Council from taking action. And the Russians, not surprisingly, blocked the Security Council from acting.

In response to that, the case was referred to the General Assembly. The General Assembly, by a substantial majority, adopted a vote that deplored Russia’s invasion of Ukraine and demanded that Russia cease its use of force against Ukraine. The vote for that was 143 in favor and five against. (There were 35 abstentions, which is interesting.) But decisions of the General Assembly are essentially seen as recommendations; they have no legally binding force of the same kind that decisions of the Security Council would have. We’ve also seen other decisions by international bodies. Ukraine brought a lawsuit in the International Court of Justice. Although that case only been through its earliest stage, the so-called provisional measure stage, the court adopted a quite clear decision demanding that Russia suspend its military operations. Of course, Russia disregarded both the decision of the General Assembly and the order of the International Court of Justice.

Does this highlight the limitations of the UN, that a country can violate the charter of the UN and still have such power?

Read full article and watch video with Q&A session at 

Stanford’s Allen Weiner on Russia’s Invasion of Ukraine and the Laws of War