Modern democratic states of the world make a lot of efforts to ensure national security, which is one of the priority areas of state activity. In recent years, you have observed armed aggression on the part of individual states, evidence of which is the illegal invasion of the territory of Ukraine by Russian troops in February 2022 and the commission of a number of war crimes by them. The article uses general and special scientific methods. A war crime is a violation of international humanitarian law or national legislation by a serviceman or other person participating in an armed conflict or involved in military activities, with the aim of harming the civilian population, prisoners of war, objects of cultural heritage, etc. Such acts may include, for example, murder, torture, violence, sexual crimes, ethnic cleansing, violence against children, forced displacement of populations and other crimes that entail responsibility under international law. The specified crimes should certainly be considered crimes against humanity, because they are particularly brutal and massive, as well as being exclusively intentional in nature, and are a serious threat to the humanitarian situation both in a specific state and in the whole world in general.