 The next year, Libya and the United States signed an agreement under which the United States also obtained military base rights, subject to renewal in 1970, in return for economic aid to Libya.The most important of the United States installations in Libya was Wheelus Air Base, near Tripoli, considered a strategically valuable installation in the 1950s and early 1960s.Reservations set aside in the desert were used by British and American military aircraft based in Europe as practice firing ranges.