I thought aircraft and balloons are lower altitude and considered fair game?
I remember reading how the USSR shot several of our U2 aircraft down..what was his name? powers? I know in WW2 Sweden even though neutral claimed a high number of enemy aircraft shot down. Both Soviet and Nazi.
Thought it was S.O.P. To defend your “air”space?
Apparently it’s a high altitude balloon that’s flying above regular airplane traffic airspace.