There was zero chance the Royal Navy fleet would have been defeated, let alone surrendered to Germany. Plans existed to move the royal family, the entire government, navy and as much of the army as possible to Canada. Furthermore there was zero chance that a German invasion would have succeeded. Of course that was not widely known at the time. The fleet would have been scuttled before handing it to over to Hitler.
I don’t think the fate of the Royal Navy entered any Americans’ minds in terms of isolation before Dec. 7 of 1941.
“Furthermore there was zero chance that a German invasion would have succeeded”
Well if they just put on orange life jackets and jumped into dinghys and demanded “asylum” upon arrival it would have worked out fabulously!
It was certainly on FDR’s mind. He was after all, Assistant Secretary of the Navy during WWI.