State aircraft, safelife.. But, you knew that. In sovereign airspace, no permit required, but still have to abide by any FIR standards—cruising levels, equipage, etc. Spain restricted US military aircraft from conducting AAR over Spanish sovereign airspace, so we squeezed thru the straits. I’ve seen three different cells refueling at once there.
I was denied entry into Peruvian airspace, including their FIR, not long after they shot up a C-130. Not using a C-5 to establish international rights, I did a 135⁰ turn avoided their FIR with their dubious claim of 200nm. Big difference between “sovereign” and “international” airspace.