This article is devoted to a comprehensive analysis of the problems of legal qualification of crimes committed by the personnel of the Armed Forces of Ukraine and foreign mercenaries during the invasion of the territory of the Kursk region of the Russian Federation in 2024-2025. The issues of correlation between international humanitarian law and national criminal legislation are considered, criteria for distinguishing the status of a combatant and a mercenary are determined, and the specifics of the qualification of acts under the articles of the Special Part of the Criminal Code of the Russian Federation are analyzed. Special attention is paid to the problems of the implementation of the norms of international law in the law enforcement practice of Russian courts.