Service members, regardless of where they’re located, are always subject to the military's jurisdiction under the UCMJ, which has
its own set of criminal laws enforced through the
court-martial process. This can sometimes conflict with civilian laws when a service member commits a crime off of a military installation where civilian authorities also have jurisdiction. So, for example, a service member who is arrested for a DUI while off of a military installation in the U.S. would be subject to the criminal jurisdiction of both civilian and military authorities.
Similarly, a service member who commits a crime in a foreign country would generally be subject to the jurisdiction of that country’s legal system as well as the UCMJ, absent a formal agreement to the contrary. This can be tricky especially if that country’s legal system lacks basic due process rights. Enter the Status of Forces Agreement (SOFA). Whenever the U.S. government is expecting to maintain military forces in a foreign country, it normally will attempt to enter into a SOFA with that country to address, among other things:
- The framework for military operations
- Foreign laws and jurisdiction over U.S. military personnel
- Legal protections for U.S. military personnel