I can't remember where I read it, but Hitler sought a 10 year long war, figuring that it would take 10 years of warfare to achieve all of his goals and have a nuke so figure with that idea he would want to or have to fight from 1939 until 1949 and just as the other poster pointed out I also read that the Nazi's own assessment was they wouldn't have a nuke until 1947 meaning that with Hitler thinking he needed 10 years, and his high command figuring that they wouldn't have a nuke until 1947, that even after getting the nuke they would still need some 18-24 more months of war for Hitler to achieve all his goals.