A few months ago I read a book about the US naval activity in the Atlantic prior to Dec 7, and my takeaway was that Roosevelt felt compelled to fight against Germany very early on in WWII, and from 1939-1941 he was pushing every boundary he could in the Atlantic theater to get closer to that goal, without directly coming out and declaring war. He understood the political realities and that the country wasn’t yet in favor of war, so he essentially fought a secret war in the western and middle Atlantic, that only the navy and administration knew about in 1940-1941. Lend-lease and helping the British were part of this push. As was the US occupation of Iceland, which had to be done by one of our two Marines Corps divisions, because the law at the time prohibited overseas deployment of the Army in peacetime (or something like that); both this and lend-lease give an idea of the sort of playing with the rules that Roosevelt was doing.
The book was “Mr. Roosevelt’s Navy – The Private War of the U.S. Atlantic Fleet, 1939-1942” by Patrick Abbazia. Written in 1975 but republished in 2016 by Naval Institute Press and available on Amazon. I didn’t notice any factual errors, despite the book being so old. Very interesting insight into the orders given to the US Atlantic Fleet, our “neutrality” patrol, and Roosevelt’s strategic intentions. I highly recommend the book if this topic is of interest to you.