A simpler and more obvious theory is that the USA's "Advanced Aerospace Threat Identification Program" (to detect and identify UFOs) was just that - meant to id

A simpler and more obvious theory is that the USA's "Advanced Aerospace Threat Identification Program" (to detect and identify UFOs) was just that - meant to identify any unknown potential threat in the sky. Any plane, drone, satellite, rocket, missile etc. is technically an Unidentified Flying Object till it is identified.