1) Whether Italy goes to war with Greece or not, Germany doesn't get involved; Barbarosa launches in mid-May instead of later June, and it launches with everything that historically was used in the Balkans and North Africa.
2) The Luftwaffe is in much better shape on the Eastern Front, with all the resources lost in the Battle of Britain, and with nothing needing to be left westward to defend against British bombing.
3) The Soviet forces will be readier than historically for Barbarosa, but they're still recovering from the earlier officer purges.
4) The Dutch almost certainly signed a peace along with the British, and will have a collaborationist government. So the Dutch East Indies will be supplying oil to Japan despite the US embargo. So Japan has plenty of oil and has no need to go to war with the US. Instead, the Germans will be able to play the Dutch oil card to get Japan to put an effort into Siberia. Probably a small one, but it means the Soviets will either be able to bring fewer troops west to defend Moscow, or Japan will seize much of the east.
5) Germany is able to freely import goods without having to run a British blockade. Even if the English-speaking powers refuse to do business, that means anything produced in South America or in the colonies of continental states. Food from Argentina, petroleum and rubber from the Dutch, tungsten from the Portuguese . . . Germany is going to be fully supplied with raw materials.
6) Germany doesn't have to spend any effort on U-boats; all the resources spent on trying to starve the British in the second half of 1940 and all of 1941 are instead spent on stuff to send east.
7) Without British bombing, German industry is more productive, spending more time producing and less time repairing.
Net effect is that the Germans are going to hit harder and earlier than they did historically, and will be significantly deeper into Russia at the end of '41. Moscow might well wind up besieged, or even fall.
Moving on past the campaigns of 1941, Soviet logistics will be seriously compromised by the lack of Lend-Lease motor vehicles, while the Air Forces of the Red Army are in much, much worse shape with no Lend-Lease aircraft. In 1942, there will be no split of effort between the Caucasus and Stalingrad; minus the need for Caucasian oil, Hitler will be able to send all of Army Group South to Stalingrad, and will almost certainly be more successful.
Could the Germans win? It seems possible. Not certain by any means, but possible.
2) The Luftwaffe is in much better shape on the Eastern Front, with all the resources lost in the Battle of Britain, and with nothing needing to be left westward to defend against British bombing.
3) The Soviet forces will be readier than historically for Barbarosa, but they're still recovering from the earlier officer purges.
4) The Dutch almost certainly signed a peace along with the British, and will have a collaborationist government. So the Dutch East Indies will be supplying oil to Japan despite the US embargo. So Japan has plenty of oil and has no need to go to war with the US. Instead, the Germans will be able to play the Dutch oil card to get Japan to put an effort into Siberia. Probably a small one, but it means the Soviets will either be able to bring fewer troops west to defend Moscow, or Japan will seize much of the east.
5) Germany is able to freely import goods without having to run a British blockade. Even if the English-speaking powers refuse to do business, that means anything produced in South America or in the colonies of continental states. Food from Argentina, petroleum and rubber from the Dutch, tungsten from the Portuguese . . . Germany is going to be fully supplied with raw materials.
6) Germany doesn't have to spend any effort on U-boats; all the resources spent on trying to starve the British in the second half of 1940 and all of 1941 are instead spent on stuff to send east.
7) Without British bombing, German industry is more productive, spending more time producing and less time repairing.
Net effect is that the Germans are going to hit harder and earlier than they did historically, and will be significantly deeper into Russia at the end of '41. Moscow might well wind up besieged, or even fall.
Moving on past the campaigns of 1941, Soviet logistics will be seriously compromised by the lack of Lend-Lease motor vehicles, while the Air Forces of the Red Army are in much, much worse shape with no Lend-Lease aircraft. In 1942, there will be no split of effort between the Caucasus and Stalingrad; minus the need for Caucasian oil, Hitler will be able to send all of Army Group South to Stalingrad, and will almost certainly be more successful.
Could the Germans win? It seems possible. Not certain by any means, but possible.