Well, actually only a very limited number of European airlines is dependent on the US market, the ones most exposed are KLM, British Airways and Aer Lingus. Other like Lufthansa for example generate less then 20% of their turn-over with flights to North-America, especially for LH the impact wouldn´t be too hard as they could re-route their traffic via Canada if necessary.
Delta Air Lines for example is heavily dependent of feed from Europe, mostly at their main hub in Atlanta, the same applies to Continental, US Airways and United which are all in a less stable position then most European carrier. Cut some US carrier their Europe networks and a good deal of domestic flights drops below break-even, especially comparably low-yield regional flights and short hops.
Pete, YOUR president has started with this crap, Europe is just responing at a field where he can feel that he has done something wrong. BTW, do you know that for every job saved in the steel industry 8 jobs in related industries in the US will be cut due to higher prices, especially in the car production? Just to get some facts straight...