We are in the final stages (interviews in a month) and my husband raises the question about the what ifs - meaning what if he is offered an outstanding job opportunity back in Canada (he is in the entertainment industry so there is the potential), and it would mean only if he was making BIG $$ ($500K+). As American citizens we would be taxed on our "world income". So after paying nearly 50% of our income to the Canadian Government, how would the US government figure out how much we would owe to the US? If we were to net $250,000 in Canada, would the US account for what we paid already?