[dfwgator]

I think we would have ultimately provoked Nazi Germany into war by continuing to ship to Britain, and the first time a US ship was fired on, would have provided us with the Casus Belli to declare war on Germany.

[CougarGA7]

I wouldn't be so sure. The Nazis began engaging U.S. ships after FDR authorized U.S. warships to escort convoys into the Atlantic. In September of 1941 the USS Greer was attacked by a U-boat though that attack failed. This was followed by an attack on the destroyer Kearny on October 17th which seriously damaged that ship and the more famous U-boat attack on the Reuben James on Halloween in which the destroyer was sunk. Maybe with the fact that the U.S. was now officially at war, another U-boat attack would be Casus Belli but I don't think it would be a sure thing.