Legality of the Russian invasion of Ukraine

The Russian invasion of Ukraine violated international law (including the Charter of the United Nations). The invasion has also been called a crime of aggression under international criminal law, and under some countries' domestic criminal codes – including those of Ukraine and Russia – although procedural obstacles exist to prosecutions under these laws.

This article discusses the international and domestic legal provisions Russia is said to have violated, as well as the legal arguments Russia has made to justify its invasion and the responses of legal experts to those arguments. The legality of the Russian invasion per se is a distinct subject from whether individual political officials or combatants have engaged in war crimes or crimes against humanity.