My point was that absent a "Pearl Harbor" sort of event the American public was not going to sign off on the US/UK attacking the USSR. While the American public was supportive of the UK/France up until PH, and actually the German DOW (first) there was no appetite to get directly involved in the war in Europe. The American public was pro-China, and anti-Japanese however prior to PH the USA was not going to shed American blood to deal with Japan. Going to war with the USSR, after several years of a wartime alliance, propaganda about the Soviet people and their fight against Nazism, and turning a psychopath is to a pipe smoking teddy bear ("Uncle Joe") coming out and saying "the USSR represents a threat as great as the Nazis and its their turn" (true or not) without a PH type cause simply is unsaleable to the American public, and I would posit the British public as well. More than any issues about correlation of forces, or what cutting of LL from aviation gasoline to spare parts for Studebaker trucks to SPAM would do it would be about public opinion. Fighting a war of this dimension without public support is not possible.