This is false. All US military navigation systems, including the referenced drone, are primarily inertial and always have been. These systems can optionally acc

This is false. All US military navigation systems, including the referenced drone, are primarily inertial and always have been. These systems can optionally accept fine-tuning GPS corrections, but only if those corrections are within the tight (classified) error margins of the inertial navigation system. It is a misconception that the US has ever used GPS for primary guidance in weapon systems; even cheap throwaway weapons like JDAM are primarily inertial. The kind of influence possible via manipulation of GPS is measured in meters. State-of-the-art INS technology is now good enough that the US military is considering phasing out GPS corrections for some newer systems. GPS was designed for the purpose of accurately measuring the Earth during peacetime to build a precise model the world that could be used for inertial navigation systems in wartime. It was never intended to be used as a critical navigation system since it could be trivially destroyed by the Soviet Union when it was designed. Civilian systems tend to not concern themselves with this vulnerability and therefore happily use it for navigation.