I trained a lot of European pilots back when I was a CFI and several of them now have airline pilot jobs. I can tell you this: most of them are looking to come back to the USA and work here. The pay is better, but the job security is not. The airline flying that is done in Europe is contract based. Meaning you sign a piece of paper that says you have a job for X amount of months and then its up to the company to decide if you can stay or not. Only ONE of the guys I know was offered an additional contract after the first 18 months. The others go through weeks/months without an interview after their contracts have expired. Its though being an airline pilot over there to start, but if you can fight your way through the brush it seems like it really pays off in the long run.