As in above… In military airspace native language is used, English only “required” in civilian airspace/ATC/Int. … in every country.
That’s incorrect. Military pilots in my non-English-speaking NATO country exclusively use English when speaking in the cockpit. English is also used for fragging etc., e.g. “OCA” instead of a native variant. I suspect it’s the same in many other NATO countries as well, where interop inside NATO is a key element. Conversely, using our own language is permitted (but discouraged) for civilian traffic inside our FIRs.
During my army career we used a lot of English as well.
Btw, all the official UN languages are accepted in ICAO ATC: Arabic, Chinese, English, French, Russian, Spanish.
Edit: Changed wording to make it a bit clearer that we are a NATO country.