Let's say Germany and USSR no war. How can Germany lose?....
Germany will lose because Germany has no way of defeating the British Empire.
.....I would say the UK would have to sign a truce and the USA won't get involved....
. Hitler naively banked on the British asking for a truce after the Battle of France because he simply had no other options. U-boat blockade? Tried that in WW1, didn't work out so well. And the
Kriegsmarine is too tiny to invade Britain, let alone try and invade the overseas Empire. Churchill was correct in pointing out that WW2 with Occupied Europe was simply a repeat of the Allied blockade of the Central Powers from WW1, it's just the front is now the French coast. In WW1, once the frontlines stabilised, the rest of the War was the Allies blockading Germany into submission. The Germans in 1940 still cannot produce enough war material to win, and Hitler has the constant worry that Stalin is going to pick his time to invade via Poland or Finland or both, or - worse still - Stalin will invade Romania and seize Germany's oil supply. As for the USA, they are climbing out of the hole from the Great Depression, and Roosevelt was only too happy to take foreign income from arms exports to the Allies. Lend-Lease was actually a way of increasing that income, just on a long-term basis. Roosevelt has no intention of joining the European war, and if Hitler hadn't declared war on the USA it is probable that the USA would have just fought the Japanese. But, the USA presented a massive industrial base for the British that was untouchable by the Germans.
So Germany cannot defeat the Empire, which has safe production facilities in the Empire and USA, out-of-range of any German bombers, whilst their own industrial base is being hit every night by the RAF. Germany also does not have enough essential supplies like tungsten and oil. So the longer the War goes on the worse it gets.
....Japan would be the fly in the ointment but if USSR is selling oil to the Japanese then the US embargo could be overcome and no need to go to the Dutch East Indies....
Yes, but you need to completely ignore the realities of 1940/41 to expect Stalin to supply oil to the Japanese. The Soviets and the Japanese are facing off in Mongolia, and the Soviets are hoping to get their Communist chums in China to take control, which means the Chinese Communists are also fighting the Japanese. No way is Stalin ever going to sell oil to the Japanese! The Japanese were completely reliant on the USA for oil in 1941, which is why Roosevelt's move to licence oil exports was such a blow. Roosevelt did not intend to provoke a war, he just hoped it would give him leverage over the Japanese. If the Japanese don't go to war, they risk losing China, and the Japanese Imperial system just cannot cope with any form of lost face.
....USSR and Germany are more in common than different but of course there are always ghosts in the machine.....
But the Soviets and the Nazis are always going to be looking for the opportunity to stab the other in the back. Hitler beat Stalin to the punch, but it meant going to war at least two years too early for the German industrial plans. If Hitler had waited, the Soviets would have invaded Poland by 1942.
....Germany lost in the East because of vast distances and logistics and bad weather but if the USSR invades then these problems disappear and you have proven war machine fighting on home soil.
True, but just as the Germans have no means of defeating the British Empire in 1940, the Germans have no way of defeating the Soviet Union without actually invading Russia, which brings us back to the same insurmountable industrial and logistical problems. Suppose the Soviets invade in June 1941, and the Germans fight them to stalemate, they still have to fight all the way to Moscow, they just now have further to go and in less time before the Russian winter. And all the time the Soviet factories, safe behind the Urals, are churning out war material at a much higher rate than Germany can even if the RAF weren't also hitting them nightly. Net effect, Germany still loses.