From the Document: "On June 11, 2020, President Trump issued Executive Order 13928, authorizing sanctions against certain individuals involved in the International Criminal Court (ICC) Prosecutor's investigation of whether U.S. military and intelligence personnel committed war crimes during the conflict in Afghanistan. The ICC is an international tribunal created by the Rome Statute to serve as the first permanent tribunal to try individuals for 'the most serious crimes of concern to the international community as a whole.' Currently, 123 countries are parties to the Rome Statute, but the United States is not, having first signed the Rome Statute but later withdrawing its intent to join. This Sidebar outlines the basis upon which the ICC Prosecutor may initiate investigations; discusses the disagreement between the United States and the Prosecutor about the legality of the request to investigate the actions of U.S. personnel; and assesses whether the United States may attempt to stop the investigation."
CRS Legal Sidebar, LSB10505
Congressional Research Service: https://crsreports.congress.gov/