-If you are in country with a different language, never assume that they don't know your language. I worked retail while in University. Two Austrian tourists came into the shop and started saying all sorts of rude things about Americans in German, assuming that they wouldn't be understood. They were shocked when I addressed them in perfect German. (Which I have since lost! )
Kind of off topic, but I had a very similar experiance.
I spent a year in Germany, and towards the end of it I was walking down the street and these two very loud, raunchy American boys walked behind me and started saying pretty innapropriate things (least of which was commenting on my booty!). I slowed down to tie my shoe against a wall and as the passed I yelled "I'm American by the way!" They cursed and laughed...very interesting!
As for the politics thing, it depends on the company. My host parents wanted to hear all about American politics, thought it was facinating.