I remember when my Navy ship visited Athens, Greece, about 30 years ago. Before we could go on liberty we had to view a recorded lecture from a Marine Lt. Colonel from the U.S. Embassy. Being a former Marine I loved it because he told it like it was in that frank way that only a Marine can do.
Some things I remember from it, and it lasted 45 minutes: "Number 1, you are in Greece and they couldn't care less that you are an American citizen. Number 2, be careful of your hand gestures because this one means one thing to you, but it means something obscene to the Greeks. If you do this gesture to a Greek woman her husband or boyfriend will likely kick your ***. If #2 happens there is nothing we at the embassy will do about it, and your *** will remained kicked. Do not think about getting even for having your *** kicked unless you want to experience a variation of the movie Midnight Express, if you get my drift. That is the way it is here and if you can't accept it then stay on your ship and don't make life difficult for me and my staff." I wish I had a tape of it. It would prove useful to many Americans.