[GATOR NAVY]

The "obey" part probably depends on how the chain of command works, but military courtesy is always expected. I work on a joint base, and I salute JMSDF officers as I would any USN officer.

[AEMILIUS PAULUS]

I can imagine when a G.I. is placed under the command of a foreign officer then obedience would be required. Plus I do imagine that ordinary military courtesy is required towards allied officers. It would be a little strange-feeling wise-as we take an oath to our constitution not to another government. Thanks to all for the response to my question.