If I’m in a foreign country and people around me are saluting their flag, should I salute it, too? Is it up to me whether or not to salute it? Or would it be an error in protocol to salute the flag of a country I’m not a citizen of?
I imagine members of the military encounter foreign flags of friendly nations often, in joint exercises and such. Are they required, permitted, or prohibited from saluting a foreign flag?
One is not obliged to salute a flag not his/her own, though it is acceptable to do so if it does not trespass on individual scruples.
What should be done is to stand out of respect for what the flag means to its own nationals.
The above refers to civilian U.S. citizens; what is appropriate for U.S. military or for non-U.S. nationals with reference to flags foreign to them is a quite different questions.
I am in the US Army and stationed in Korea. When I am in uniform and the National Anthem of Korea is played, I am REQUIRED to stand at attention and salute their flag, just as I would if the national anthem of the US was played. This goes for all Allied and US friendly countries.
When I am in civilian dress and the national anthem plays at a soccer game or something, I just stand at attention.
As long as you stand and don’t talk and attempt to show some form of respect, you are doing the right thing. It’s basically your choice as to how you want to show respect. But basically, the only wrong thing would be to do something that blatantly disrespects that country or offends its citizens.