The military of the United States is deployed in more than 150 countries around the world, with 172,966 of its 1,372,522 active-duty personnel serving outside the United States and its territories. Most of these overseas personnel are deployed in combat zones in the Middle east, as part of the War on Terror. Many of the remainder are located at installations activated during the Cold War, by which the US government sought to challenge the Soviet Union in the aftermath of World War II.