We can all say "green card," getting one is totally another thing. I dont think the US has issued a green card to a foreign national on the basis of his/her application to be employed as a pilot. Not in living memory if ever. The other way across the pond is conceivable. The FAA will not validate a euro license beyond ppl, but many JAA authorities will validate an FAA atp, usually if expeience levels are appropriate and a propective employer petitions.