Just for the record, you do not need a Green Card to work in the United States. What you do need is an L1 visa and you need to have a qualification that is attractive to the airline concerned. I flew for a Part 121 carrier for 3 years and nobody seemed to resent my presence in the USA.
I also worked in Europe for 6 years and I was very far from being the only Brit working there.
Aviation is a global business and the sooner that some of the hotheads on this forum get to realise that the better.