By - wessneijder
What the commenters were saying is, what would have happened if Germany and Japan were perfectly coordinated?
If Japan had attacked Russia instead of Pearl Harbor, what would have happened? If Japan had threatened Suez Canal traffic, what would have happened? Pick either of these 2 scenarios and you might have a WW2 with a lot more dead bodies than the war we got in real life
The problem with Japan-attacks-Russia in December 1941 (or earlier) is that it would be entirely to the Germans' advantage, and none to the Japanese.
The Japanese were looking at the collapse of their entire economy in less that a year without an attack somewhere to get the oil that the US embargo had cut off from Japan. That oil was in Java and surrounding areas. The tankers that would carry oil to Japan (after seized the wells from the British and Dutch) would have to go by the Philippines and their bases. The Japanese attacked the US possessions to try and make that flow of oil safe. Having determined on attacking the US, a surprise attack on Pearl Harbor to cripple the USN - like the attack in 1905 on the Russian fleet, which most of the senior staff could personally remember - was an easy leap. The Japanese also had experience fighting the Russians on land more recently; the 'Khalkhin-Gol' campaign in mid-1939 had been a severe defeat to the Japanese Army inflicted by a relatively small Red Army offensive.
Attacking Russia would not solve the main problem for the Japanese - oil shortage.
You are exactly right. The Japanese would have got a terrible deal out of it and their oil crisis would have been debilitating
Their cooperation would have still been very valuable, either on the Indian region you mentioned or just in general.
If the Japanese were to be able to stop merchant-ship traffic to and from India by disputing control of the Indian Ocean, it would isolate India. A long-term campaign using major fleet units - based, for instance, at Surabaya - might have allowed it. It would change pretty much everything about the war in Southeast Asia. (There was no direct rail link from Iran into India at the time.). The effects of that are hard for me to see - but it might embolden separatists, and the Japanese to try and push into India in 1942. Certainly the Japanese would have air superiority in the area.
The Guadalcanal campaign - and its follow-on campaign up the Solomons and in New Guinea threatened the giant base at Rabaul. Rabaul's loss would threaten the oil fields on Indonesia, and leave the Japanese with no 'fortress' southeast of the Philippines at all. (In the end, the Allies neutralized Rabaul, and left it to die on the vine.)
With the losses at Midway, the Japanese were left with only one "Air Fleet" (two fleet carriers, three light carriers). They didn't think they could go up against more than one major fleet unit of the Allies at a time. So it was either west (Indian Ocean) or east (Solomons). They were short of pilots already; the reason Shokaku and Zuikaku didn't join in Midway was mostly because they were short of pilots.
Also, a commitment to the Indian Ocean was an open-ended proposition. The IJN would have to keep surpressing shipping links to India - and maybe invade Ceylon - for the foreseeable future. Kicking the US out of Guadalcanal would end the Solomons threat, and leave the Japanese with only one threat to Rabaul - from New Guinea. If the US Marines at Guadalcanal could have been destroyed, the IJN might \*then\* be free to have another look at the Indian Ocean idea.
Another factor was the IJN's attitude of naval warfare. They adhered very closely to the fleet-destroys-fleet view; if you destroy the enemy fleet, the merchant ships are easy game. The problem is, if you don't destroy the enemy fleet, your doctrine doesn't allow an anti-merchant-ship strategy. The USN sent its submarines to hunting and killing the flow of supplies - including oil - right away. The Japanese sent its submarines on scouting and anti-combat-vessel missions, and generally ignored merchant traffic. Even in the Indian Ocean raids, they didn't make a concerted effort to interdict merchant traffic. They hunted enemy combat ships. When they ran out of RN targets, they went away.
As far as Iran goes, the Allies had been using the 'trans-Iranian railway' (running north to south) to get supplies to Russia since August 1941 (both Russia and Britain invaded Iran and set up a puppet government to allow the railway to operate and be improved.)
If the Japanese could take India and threaten Iran, they might be able to not only interrupt the Iranian rail connection to Russia (which sent far more equipment and supplies than the North Sea convoys or US-Vladivostok route), but threaten the British Middle East position. And that would not require the Japanese to attack the Russians at all; they were already at war with the Brits.
The Germans were quite aware that the Japanese were not all that interested in an attack Russia, and preferred to keep them neutral while the Japanese had at the US and British Empire forces. It was a matter of the Germans asking for something they thought was possible, I think.