I'm looking at you, Avatar, Aliens, Stargate, Contact, Close Encounters, Earth Stood

Since US owns the GPS satellites, it seems inevitable that the US military would be involved. However, don't worry, current US administration seems hellbent on burning everything down so perhaps other countries who don't have this problem will get to take over first contact and response. The destructiveness may well take a generation to fix.

Avatar was private military mercenaries. Former military.