"What if: Japan Hadn’t Attacked Pearl Harbor?" Topic

"Japan never seriously considered the following scenario—but might have been wise to do so.

On December 15, 1941, naval and air units of the empire of Japan suddenly and deliberately attack the Dutch naval squadron at Batavia in the Netherlands East Indies (present-day Indonesia). They destroy or damage all five cruisers and eight destroyers, leaving fifty-five-year-old Vice Adm. Conrad Emil Lambert Helfrich with only twenty submarines and numerous but frail torpedo boats with which to retaliate.

Shortly thereafter the Japanese Sixteenth Army invades the Dutch portion of the island of Borneo—scrupulously avoiding portions administered by Great Britain— then rapidly follows up with attacks on Java, Sumatra, Sulawesi, and other major islands in the East Indies archipelago. The puny Dutch garrisons are swiftly overrun, the Dutch naval bases at Batavia and Surabaya quickly fall, and by the end of February 1942, Japan has secured the Netherlands East Indies' cornucopia of petroleum, natural gas, tin, manganese, copper, nickel, bauxite, and coal…."
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Amicalement
Armand

Yep – Japan gambled, and lost (Yamamoto was famous for his gambling).

The Japanese had to try and knock USA out of the war before it got going, Same as they did with the Russians in 1904. Or else they would not have been the Japanese, The thought patten in 1941 made it so.

Japan attacked in the sweet spot where there first new ships and aircraft were coming on-line and the US were about a year later. If they had delayed for just 18 months the delay would have been disastrous. In every class of ship the US was outbuilding them and our armies and air-forces were expanding.

Would the Philippines have remained as weakly defended or would the ground/air/sea forces be dramatically reinforced (with the new Japanese threat). Would the US stay neutral or after a declaration of war would the dozens of new submarines and hundreds of additional fighters/bombers based out of the Philippines make it a disaster for the Japanese merchant marine.

The problem with changing the scenario on one side usually does not look at what the other side would do.

The problem with changing the scenario on one side usually does not look at what the other side would do.

Without a direct attack on the US that still leaves the problem of an isolationist America's reluctance to go to war. Pearl Harbour gave the Americans the will to fight. Would an attack on the Dutch do the same?

The US declared an oil embargo after Japan's actions in China.

Japan got 95% of it's oil from the US at the time.

There was no way in hell the Japanese would not have attacked the US.

We wouldn't have that awful film for starters…

Both the US and Japan would clash sooner or later. The US was trying to protect interests in China and didn't like Japan trying to become the dominant power, just as the Japanese saw that the US was the main hurdle to their control of Asia.

The attack on Pearl Harbor was a masterstroke, but the follow up failed miserably I don't see a scenario where Japan will only ever do slightly better than they did historically, but lose once the US gets on full wartime footing.

The attack at Pearl Harbour was actually a military strategical failure and only a propaganda success as they missed the Aircraft carriers that if damaged (at least a few of them, the US having actually only five operational…) would have actually put the US out of the game in the Pacific for many months, given the Japanese superiority in both aircrafts carriers and trained navy pilots they had at the time.

Would the Philippines have remained as weakly defended or would the ground/air/sea forces be dramatically reinforced (with the new Japanese threat).

The Japanese hit the Philippines at one of the last "right moments". If they attacked a year earlier (1940) then they would have encountered a very weak foe who was armed with almost no modern weapons. The US need to not want to antagonize the Japanese plus its horrible defense budget led to a US force operating truly obsolete aircraft, and a tiny number of them, a very small garrison (a very understrength Philippine Division with a few coastal units and the 26th Cavalry) and very few Filipinos under arms. They would have taken Luzon in just a couple of weeks and Bataan very quickly after that.

But 1941? By that time MacArthur had convinced the US to strongly reinforce the garrison. First P35s then later P40s were sent to the FEAF along with waves of B17s. Douglass Dauntless dive bombers and even more P40s were in crates and were being shipped to the Philippines even as the war broke out. The Navy had also deployed a force of more modern submarines to reinforce the Asiatic Fleet.

Worst still for the Japanese were the two additional regiments of US troop,a battalion or so Grant tanks, and a wide array of artillery and service and supporting troops that were in the process of heading to the Philippines. These troops would have provided the corps and army level forces that would have supported the Northern and Southern Luzon Forces and made them into true corps level formation. The two US regiments would have relieved the Philippine Scout regiments whose troops would have been used as more trainers for the Philippine Army or would have been used to bring other Philippine formations up to strength. Finally, the battalion of Grants would have seriously strengthen the US armored force in the Philippines and that would have been a major threat to the Japanese forces operating on the Luzon plain. The Grant's guns could easily kill any Japanese tank in the campaign and its armor was virtually proof against their guns. That battalion could have checked most of the major Japanese thrusts and could have reeked havoc on the more poorly armed Japanese.

Finally,but not least, each month Japan stalled would have given the US more time to train and equip the Philippine Army. One of the big elements in play for the Japanese was that the PA wasn't fully trained and its formations melted, for good reason, on contact with the Japanese ground forces. Delaying even longer would have given those troops more time to train and to become familiar with their weapons.

A delay by 6 months would have left the Philippines with a truly formidable garrison that would be armed with some of the best weapons that the US had to offer during this part of WWII. As it was the Japanese were almost too late attacking the garrison.

Here's a great book that details the US efforts to prepare for the war in the Philippines. It really shows you how determined the US was to defend the Philippines and what forces were heading to reinforce the garrison.

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It is a bit of a dry read though, but interesting if you really want to know the state of the garrison just prior to the war kicking off. It also gives some insights into how the US was suddenly able to send forces to Australia.

If they had not attacked the US … they wouldn't have got nuked … twice. IIRC they agreed[well most of them] to surrender on this date, 14 Aug 45 after the second nuke …

Saved a lot of Allied and even Japanese lives …

The US Army Historical series (Green Books) volume on the Fall of the Philippines has a lot of good information on the American build up. The Grants never made it, but there were two battalions of M3 Stuarts (which against the Japanese were nearly as formidable as the Grants would have been). Sadly, they were horrible misused and accomplished almost nothing. Interestingly, a ship load of British Bren Carriers were caught there by the start of the war and the Americans pressed them into service as well. But the bottom line was that MacArthur royally screwed up the defense, so even if those additional forces had arrived they might not have made all that much difference.