When in France, kissing cheeks instead of shaking hands is casual and customary. The Dutch take it a step further, insisting on three pecks as opposed to the traditional two. And the lovely Swedes would never take a sip of wine before looking everyone in the eye.
I'll bet that most who travel to Mexico for margaritas and mole would slip an occasional "si, por favor" and "de nada" into their daily banter, as a teensy tiny homage to the land they're visiting.
But when the director of the CIA says that he has "an excellent idea" where one of the most notorious criminals of modern times is hiding -- but is trying to figure out how to capture him without stepping on the toes of foreign nations -- balking is the only polite reaction.
ps. Read this.