I've found outside the USA they tend to be confused when I tip. Or they will look me right in the eyes and say, "American, yes?".

I've found that when I go to restaurants outside the U.S. without speaking their native tongue they often ask where I'm from. Answering that you are from the U.S. will make the servers overly friendly and then they will ask for a tip.

You expect us to tip when we visit your country, why can't we expect you to tip when you visit ours?

Servers taking advantage of the tendency for Americans to tip shouldn't be conflated with anyone else traveling to the US.