Thats a very good point, the US would no doubt have drawn A/S forces back toward home waters rather than deploying them in the mid-Atlantic. However, by that stage convoys had their own organic ASW air elements, and the 'air gap' had been closed, so it wouldn't necessarily have made life any easier for the U-boats that managed to make it out into the mid-Atlantic. Therefore, I don't think that the war would have gone on any longer as a result of V2 strikes on the US mainland. Nor would the propoganda value have been huge, as the German armies would still have been getting stuffed by the Allies on both fronts, regardless of how many V2s hit New York. Very much a case of far too little, far too late,