Obviously we navigated acceptably, including aircraft, long before the development of GPS in the 1970s. GPS is easy and precise and can make risky edge cases (l

Obviously we navigated acceptably, including aircraft, long before the development of GPS in the 1970s. GPS is easy and precise and can make risky edge cases (like very low altitude flight) safer or allow higher density in air spaces and such, but it's not necessary particularly not at the government aircraft level. Inertial guidance, ground based Doppler navigation systems, and even automated celestial navigation in combo can produce great results just at a much, much higher expense. That isn't an issue for the leader of a major power though. The SR-71 was a cool example of a system that used a hybrid of automated celestial navigation and inertial. Fully self-contained.