There were many steps that were involved in moving the US towards long-term commitments to an overseas presence. These could include:
- The creation of NATO. This committed the US to defending Western Europe from the Soviet Union. This led to the creation and maintenance of US bases in places like Germany and Turkey.
- The Korean War. This led the US to station troops in South Korea on a permanent basis. These troops remain there today. This also, one could argue, led the US to keep large military bases in places like the Philippines, Japan, and Guam.
- The French surrender at Dien Bien Phu and their subsequent withdrawal from Vietnam. This led to the US putting more and more military personnel into the country, culminating in the massive buildup after 1964.