Have any countries at war played each other in International competition?

That’s a very echnical constitutional issue that applies only to the United Stares. When speaking in an international context, that definition needn’t apply. For the purposes of the OP, it seems go me that any open military conflict that the U.S. has been involved in should qualify, especially if it has some degree of international imprimatur.

If all Americans stare at you in unison, you’d better do what they ask for, or else. :eek: