I'm not entirely convinced the U.S falls for the bait and declares war on Hitler and Mussolini under Wilikie. We were attacked by Japan, and a Wilikie administration would focus on them.
Most likely, we go to war in the Pacific, Europe remains largely an undeclared war for the U.S until Japan is defeated (at least in 1945 when the nukes are ready, possibly sooner given there are no American troops in Europe), followed by a quick pivot to Europe and declaration of war, just in time to knock out Germany and Italy in one fell swoop in mid-to-late 1945-early-1946.
As for Russia, Lend-Lease continues as is, with no real changes, and probably ramped up with the formal absence of American troops in Europe for both Britain and the Soviet Union.
The US didn't declare war on Germany or Italy, Germany declared war on the United States following Pearl.
