What if Japan chose Middle Eastern oil instead of Dutch oil

[glenn239]

As I understand it, those 39 ships were the entire Japanese tanker fleet.

The Japanese tanker fleet in Dec 1941 was about 650,000 tons, including the 10 fleet tankers.

Any idea how much shipping the Japanese captured? I'm pretty sure I've read of a fair number of reflagged vessels.

USSBS has this info. About 900,000 tons, IIRC.

[Jon G.]

...
The Japanese tanker fleet in Dec 1941 was about 650,000 tons, including the 10 fleet tankers...

Is that GRT, dwt, displacement or another ships' weight denominator? The difference is not unimportant. The figure I gave upthread is GRT - that is, for internal volume.

[PeterOT]

...Interesting that Japan still had 4 million tonnes at war's end. I've heard that US subs were so effective that by war's end not even the Sea of Japan was safe. Wonder if lots of that shipping was either doing short runs within the Empire or just hiding in port?

That kind of surprised me as well. By the end of the war mines were becoming as big or bigger threat than the subs (although the subs were responsible for some of the mines). My impression is that a lot of ships were just sitting in port due to lack of cargo and fuel as much as anything else. I wonder how much of that shipping was also under repair?

DOH! Lack of fuel was way too obvious, no wonder I missed it. That tanker fleet was WAY too small for an island nation with a big navy about to go to war with the entire Western world. Imagine being the folk trying to work out which ships got what fuel as the stuff completely dries up - talk about your sucky jobs.

[glenn239]

Is that GRT, dwt, displacement or another ships' weight denominator? The difference is not unimportant. The figure I gave upthread is GRT

GRT. Includes one military tanker currently in use as a submarine tender (but still capable as a tanker). Figure about 720,000 tons carrying capacity. Nailing the precise Japanese tanker fleet in 1941 was difficult because the Japanese converted other types to tankers as need be.

That tanker fleet was WAY too small for an island nation with a big navy about to go to war with the entire Western world

The carrying capacity of the Japanese tanker fleet listed above. The fuel capacity of her war fleet (11 BB, 9 CV, 18 CA, 20 CL, 110 DD) was about 180,000 tons.

[Von Schadewald]

Just how much more successful could the 1942 Indian Ocean Raid have been for the Japanese more than in OTL - absolute best plausible case scenario?

Could it have changed the course of the war?

And worst case scenario for the Japanese?

[Mostlyharmless]

Just how much more successful could the 1942 Indian Ocean Raid have been for the Japanese more than in OTL - absolute best plausible case scenario?

Could it have changed the course of the war?

And worst case scenario for the Japanese?

It could have have been very much more successful. Had Nagumo or one of his staff asked where Dorsetshire and Cornwall were going and if there might be other ships along their course, or if the aircraft shadowing the cruisers had reported enemy carrier based aircraft, Nagumo had time to locate and attack the Somerville's large carriers. Had the carriers been attacked and crippled, Nagumo might have remembered the criticism of not finishing off Pearl Harbor and continued attacking over the next few days until almost all of Somerville's fleet had been sunk.

That could have changed the course of the war. Just not the war being fought by the Japanese. It would have allowed a cruiser force such as Ozawa's to cut off supplies to India (and thus to China), oil to Australia from the Middle East, supplies to British forces in Egypt and supplies going to Russia via Iran (well at the time going to build the docks and road to Russia). You can thus suggest that Rommel might have taken Alexandria etc. Even if the change is not so dramatic, the RN is going to need to find at least one new aircraft carrier to defend the Indian Ocean and given the need to watch Turpitz, may not be able to carry out Operation Pedestal. However, none of that is going to help Japan at all in its war with America. In fact Nagumo will certainly lose some aircraft and be worse off for subsequent operations. The best possibility for the IJN is that Yamamoto will have to modify the plans for MO and Midway because the Kido Butai needs re-equipment.

The worst case scenario for the Japanese is that the British succeed in a night torpedo attack on the Kido Butai and the Japanese are the first to discover the problems of ruptured tanks of aviation fuel.

[Simon K]

Which is why Ceylon would have been a much more suitable place for the RNs main far east base as opposed to Singapore.
It would have provided more of a defense in depth covering the Western Pacific and Indian oceans. deterrence did not protect Malaya, so the fleets basing there (remember it was never used, except for force Z) was irrelevent.
Singapore should have been a light fleet and airbase. Much more air.

[Von Schadewald]

If the Japanese had landed a decent force on Madagascar before the British invasion, together with I submarines, would the Vichy have joined with them to resist the invasion?

Could a Japanese base plausibly have been set up that would have made a worthwhile threat against Allied shipping to the Middle East, Australia and India?