From the Document: "In the days after Russia's invasion of Ukraine on February 24, 2022, many countries [hyperlink] condemned the action as a violation of international law governing when countries may use force against one another. Since then, several observers, including the U.S. Secretary of State [hyperlink] and other foreign [hyperlink] government officials [hyperlink], have cited evidence that the Russian military has targeted civilians, struck protected sites, and taken other actions that violate international law regulating the conduct of war. This Legal Sidebar provides a brief introduction to the international legal framework governing the use of force in the invasion of Ukraine and concludes with a discussion of avenues for accountability and options for Congress."
CRS Legal Sidebar, LSB10710
Congressional Research Service: https://crsreports.congress.gov/