Every empire since Portugal has eventually lost its foreign bases

Evidence

A succession of empires and world powers through the centuries have amassed and subsequently lost most if not all of their foreign bases, either by force or divestment. Following in the footsteps of Portugal, Holland, Spain, and France, Britain had to shutter most of its foreign bases in the midst of an economic crisis in the 1960s and 1970s. The United States is headed in that same direction. The only questions are when and whether the country will close its bases and downsize its global mission by choice, or whether it will follow Britain’s path as a fading power forced to give up its bases from a position of weakness. — David Vine, Base Nation_ How U.S. Military Bases…, 1080