POD: In 1920 Leo Szilard decides to keep doing engineering at Technical University of Berlin instead of physics. He goes on to become an engineer of no historial signifcane. Though Szilard does move to the US eventually he never makes contact with Einstein so in 1939 the president is never informed of the danger of Germany developing a bomb. Therefore they never develop their own
The Germans declare war as in OTL and things continue very similar to OTL.
On the 8th May 1945 after 5 and a half years of violent and bloody fighting the German instrument of surrender is finally signed by Alfred Jodl. The Americans and the USSR now look to Japan. The USSR draw up Operation Chekharda (leapfrog)for when the Americans move the bulk of their forces to Japan for an invasion they will invade West Germany with potential plans for France and Italy to be attacked as well once the US invades Japan.
The USSR attacks Manchuko goes along swiftly as in OTL but the Americans having no nuclear weapons to drop don't force Japan to surrender.
On the 12th of October Douglas MacArthur is made General of the Armies by Harry Truman in preparation for an invasion of Japan.
The US attack Tanegashima, Yakushima and the Koshikijima Islands on the 12th October while MacArthur is promoted. They land but are caught in violent fighting and with a number of American ships damaged by Kamikaze and large American losses as they desperately try to drive the Japanese out of subterranean fortress. By the end of October the clearing is almost complete and the islands are overrun with airfields.
After months of build up the US, Britain and Commonwealth countries start Operation Downfall on the 1st of November. The largest amphibious fleet ever is assembled to launch the attacks and a massive shore bombardment to back it up. The Japanese start the battle by sending out 1,000s of Kamikaze attacks and submarines. This sinks almost 200 American ships mainly transports. It causes significant losses to the US.
The landings on Miyazaki go very well with not many opposition forces blocking the Allies. Though on Ariake the Americans suffer massive casualties and although due to the sheer weight of air and naval support they aren't driven off. They are held down on the beaches until support arrives from elsewhere.
As the US and it's allies slowly grind their way onto Japan with Operation Olympic while behind schedule still moving. Back in Europe on the 4th of November the USSR having been waiting for the opportunity launch their assault.
The invasion goes well for the USSR with only minimal Western resistance as they quickly overwhelmed in a series of fast encircling attacks.
Upon hearing about the situation in Europe the American force in Japan is forced to turn back and abandon Japan and rush for Europe as they are desperately needed to help.
As the first Soviet forces reach the Po river on 28 December the US forces land on mainland Italy while in Northern Europe the remaining forces try to cut their way to the channel coast and escape but the USSR has most units encircled and destroyed.
The Americans take Rome first but the USSR attacks back