The Lend Lease Act was initiated to, as the poster Uncle Sam holds, to support the US's allies in their war effort. "Short of War" is used to describe that the US economically was already in the war, as they provided loans, created military hardware and equipments, and heavily invested in their allies. The only thing holding them out was the public opinion, and the investment of American lives nonvoluntarily. The left side is used to suggest the public opinion, and how there were sentiments on both sides for the argument. In essence, Uncle Sam is trying to appease both sides in supporting logistically the Allies, while not forcing US men into the warfront.
