MIL Acft must broadcast outside their own national airspace
well, in peace time anyways.
basic process for U.S.:
International community is incredibly strict on Overflight, Landing, and Remain Over Night requests when traversing inside a nation's sovereign airspace as a foreign military aircraft
request must be approved by host nation.
even for POTUS flights.
they issue a "clearance number" for that flight if approved.
basically, if operations fugs up the paperwork or you as the crew don't hit your "gate' time (FIR crossing) as specifically dictated by that host nation, you're not going.
Miss your "gate time" and they'll turn your ass around at the FIR
quack
o7