Significance of Pearl Harbor in U.S. entry to WWII

January 25, 2013 8:54 AM

What if Japan had not attacked Pearl Harbor?

I realize any answer would be purely conjecture, but can't help thinking that historical scholars have already come up with well thought-out theories on the question...and that's what I need help with. How would the Second World War have [most likely] played out if Japan had not attacked the United States at Pearl Harbor? General thoughts are welcome but, again, I'm looking for credible sources where this scenario has been vetted against the geo-politics of mid-20th Century.

posted by mousepad to law & government (19 answers total)

They attacked the (US-owned) Philippines the next day, so there was still going to be war.
posted by ROU_Xenophobe at 9:13 AM on January 25 [2 favorites]

When I took Asian history in undergrad, the professor mentioned that one of the major reasons the Japanese attacked Pearl Harbour was that they thought the Americans might have declared war against them anyways (because of their aggression elsewhere in Asia). By taking advantage of surprise and attacking Pearl Harbour, they hoped that they could cripple the US and convince them that it wasn't worth getting involved in the Pacific War, and so the Japanese could be free to conquer south-east Asia, where there was oil that they desperately needed to keep up their expansion.

So if they hadn't attacked Pearl Harbour? Japan would have continued their war of aggression in Asia, which (of course) had started decade(s) earlier (depending on how you divide up the conflict).

Perhaps isolationist factions in the USA would have had more sway and prevented the US entrance into WW2 for longer, though there is other evidence that Roosevelt was promising help to Britain in the European War well before Pearl Harbour. They wouldn't have had the losses they suffered at Pearl Harbour, so I don't know what difference it would have made to the Pacific War. Also, Hong Kong and Singapore were attacked at about the same time -- I don't know how the US would have reacted just to these attacks. Maybe the pro-intervention people could have used an attack on the British territories as a reason to get more directly involved as well. (I believe that the US was already indirectly involved by aiding China, but it's been a while since I studied 20th century Chinese history).

/I'm assuming that No Pearl Harbour also means no other direct attacks on US possessions -- do you want us to assume no attacks on the territories of close US allies?
posted by jb at 9:22 AM on January 25

just a note: I don't know how many credible sources you'll find for a historical counter-factual. It's not a mode that is popular in academic history, since it ends up being largely speculation.
posted by jb at 9:23 AM on January 25 [2 favorites]

Very generally speaking, Japan was divided in December 1941 - half of the ruling elite (the Army) wanted to focus on China, half of the elite (the Navy) wanted to focus on the Pacific.

So, assuming the Navy faction would have somehow lost the argument entirely, Japan would have just focused on China.

Or, if they decided to not attack the US, Japan would have focused on the European colonies in SE Asia, and would have left the American colonies in the Pacific (Philippines, Hawaii) alone.

So it's possible that the US would not have been drawn into the war.
posted by KokuRyu at 9:26 AM on January 25 [2 favorites]

It's important to remember that regardless of Pearl Harbor, we were already in a shooting war with Germany in the Atlantic over our supplying of Great Britain (and others). We were well on our way. If you're asking "how would things have gone had there been no conflict with Japan?" then the answer is that there would likely have been a constant draw into Europe anyway, but one without the split of resources between two major theaters -- and also without the instant galvanization of American support for the war that Pearl Harbor provided. That said... yeah, American involvement in Europe was pretty much inevitable.

As an aside, this sort of question often comes up in the context of "Did FDR know it would happen?" and that's usually debunked by anyone with a functioning brain. It's like saying you want an excuse to get into a bar fight, so you willingly let the other guy break your right arm as an opening hit. ROU is right about the Philippines; that still would've drawn us into war, and in fact that's the sort of attack the US gov't did expect (and, to be fair, prepared poorly for).
posted by scaryblackdeath at 9:27 AM on January 25 [1 favorite]

Here is a sample curriculum guide from a Yale program for high school teachers. The Wikipedia article on the subject is also informative.

US entry into the war was basically a foregone conclusion. The US, under the leadership of President Roosevelt and in spite of a largely isolationist Congress, had been preparing for war since 1939, far beyond the mere provision of arms and materiel to the Allies. By the end of 1941, tensions were so high that the US was almost certain to enter the war no later than early 1942, regardless of how it happened.

A few key facts:

- Though the US had declared its official neutrality in 1939, this was abandoned in September 1940, when the US officially announced its support for Britain and openly exchanged destroyers for military bases.

- In early 1940, the US instituted its first peacetime draft. Heard of Selective Service, the federal draft registration program? That started in 1940, not 1942.

- In 1940, the US began restricting exports of scrap metal to Japan. As the Japanese relied heavily on American scrap for their industrial base, to describe this as "provocative" would be quite the understatement. But exports of oil were permitted to continue.

- In mid-1941, US forces replaced British forces guarding Iceland, and the US began attempting to protect shipping from German U-boats across the entire western half of the North Atlantic.

- In July 1941, the US imposed a full-scale embargo upon Japan, including all oil exports. This was highly provocative, and everyone knew it.

- In September 1941, the USS Greer exchanged fire with a German U-boat in the North Atlantic. US ships were given orders to shoot on sight.

- That same month, the Japanese and American governments held a summit to discuss the situation. Both sides assumed that if no agreement could be reached that war was inevitable.

- In October 1941, the USS Reuben James was sunk by a German U-boat off the coast of Iceland.

- In November 1941, the US began arming its merchant ships to defend against Japanese aggression.

- Also in November 1941, Japanese General and Prime Minister Tojo tried diplomacy one more time. If that failed, the Japanese were going to attack in December, assuming the Americans didn't beat them to the punch. For the Americans' part, there was a decision that any Japanese hostile action below the 100th parallel would not be countenanced.

So by the beginning of December 1941, whether the US was going to enter the war was no longer really the question. The question was exactly when, and who would shoot first.
posted by valkyryn at 9:28 AM on January 25 [11 favorites]

below the 100th parallel

Should that read "10th"? (Or "20th", which would cover the Philippines?)
posted by stebulus at 9:50 AM on January 25

Yeah, it's a mistake to think of Pearl Harbor as a complete bolt out of the blue. It was a surprise attack, but it was in the context of rapidly escalating tensions that were clearly leading towards war.

In this context, Japanese actions make much more sense. Pearl Harbor no longer looks like an unprovoked attack that started a war with a powerful enemy, but an attempt to take the initiative in an inevitable war by crippling that enemy's navy.
posted by mr_roboto at 9:54 AM on January 25 [5 favorites]

Well, I think you'd have to specify more closely on what you meant by 'Japan fails to attack the United States at Pearl Harbor'.

Generally, IIRC, a bunch of people believe that Japan attacked the United States fleet at Pearl Harbor as the opening stroke of a war. Japanese naval doctrine at the time centered around the idea of the Decisive Battle, an idea which had its basis in the Japanese victory at Tsushima in the Russo-Japanese war.

Now the reason Japan decided that it had to start a war with the United States was in response to an American oil embargo. This, in turn, was in response to Japan's invasion of China, which was fairly unpopular, what with the various atrocities and all. Japan felt that it could either basically withdraw from China (acceding to American demands), watch its military decline slowly for lack of oil, or seize oil by force.

Obviously, Japan chose to take oil by force. The Japanese Navy was designed to fight the American Pacific Fleet as it rushed west to defend the Philippines, despite the Japanese Navy being smaller. The Japanese plan was to whittle down the American battle line with submarine, naval and land aircraft, and night destroyer/torpedo attacks before finally crushing the weakened American fleet in a decisive battle, using its newest top secret battleships, which mounted the largest cannon afloat. Victory was to be ensured with a healthy dash of superior Japanese fighting spirit (Yamato damashii).

The American war plan for a Pacific war was first laid out in 1911, and was called War Plan Orange. It basically assumed the Japanese would assault the Philippines. The fleet would then assemble at Pearl Harbor, then attack west to confront the Japanese battle fleet somewhere in the Pacific ocean. The American war plan changed in the end of 1940, when Admiral "Betty" Stark proposed a basically 'Europe first' policy which would use 'economic blockade' against Japan while the US mounted a land offensive against the Axis. War Plan Dog basically had the US fleet adopting a defensive posture and avoiding operations in the Far East or mid-Pacific while focusing against Germany. This was the War Plan in effect when Pearl Harbor was bombed.

The rest is purely speculation. Without the shock of Pearl Harbor, America might stick with War Plan Dog. Japan is still limited by its poor logistical capacity, so probably can't invade much further. America might not decide to attack westward until the new ships start coming off the assembly line in 1942-1943, after it's clear that Hitler is in big trouble. Japan might have a bit more time to consolidate island bases, but Japan is basically in big trouble anyway in the long run.

Alternatively, trying to follow War Plan Orange might have bad results for the American fleet. American naval forces performed inconsistently at the beginning of WWII, with few Americans realizing the danger of the long ranged Japanese torpedoes; American captains were still training to form a line and try to 'cross the T' with gunfire, which presented a huge target for torpedoes. It's entirely possible that Japan sinks the American battle line somewhere deep in the Pacific, not in Pearl Harbor where they can be raised again. But Japan is still eventually in big trouble once the new carriers start coming off of the production lines.
posted by Comrade_robot at 10:03 AM on January 25

Down into the hypothetical rabbit hole:

One of the effects of the attack was to draw attention to our lack of a good navy. The ships damaged at Pearl Harbor were generally superannuated, but their loss was emblematic of our weakness in the Pacific. We already were sensitive to the possibility of a Japanese attack on the US. After the attack in Hawaii, our industrial base was engaged to meet the "war effort". This affected the US in several ways, not the least of which was to stimulate our flagging economy. Keep in mind that prior to WWII, the US was not a primary world military power, and we were puttering around our own infrastructure, with only a little left over to spare the Brits. Some of our industry, oddly enough, was tied with the German industrial base, particularly in steel. The image of the us economy as the Sleeping Giant was appropriate.

Although it's unlikely that we'd have avoided ever engaging the Japanese directly, their presence in Asia might have become better established: they were in colonial pursuit of Asian rescources, and were able to identify the West as an exploitive bogey man. Even if their Coprosperity Sphere never actually succeeded in running all the Whites out of Austrailia, you might imagine that Indo-Chinese citizens nowadays would be speaking Japanese as as second language. Historians are fond of pointing out that the Battle of Midway was a turning point in the war, because it crippled the Japanese navy and weakened its control of the area. That was a more or less fluckish loss, because we broke their code early on. Let's say that, if they hadn't attacked Pearl Harbor and stimulated our interest in defending the area, that we'd not have had a barracks filled with code breakers living in Honolulu, so we'd not have....(you get the idea).

I imagine that if the Japanese military/civilian leadership finally had attained some harmony, they could have negotiated some sort of buffer zone along the Pacific Rim with the US. I'm pretty sure the inhabitants of the area would not have been consulted about the changes of hands that held the reins, but then they were not consulted by the Dutch or the French or the British or the Russian colonialists in the first place. It's worth noticing that American OSS operatives and British Commando forces were put in place to help organize guerrilla counterinsurgents in such places as Burma, Thailand, and Indo-China. Without our help, the local forces had little in the way of resources or organization to deal with the Japanese. Even so, at least in the early days of the war, not all countries in southern Asia were equally disenchanted with the Japanese theory of booting out European influence over their internal affairs. Mountain tribes in Burma have traditionally ignored Eurpean efforts to mess with them, and the Japanese didn't find it worth their while to mess with them either. They were more concerned with Rangoon--for it's resources as a harbor, and as a gathering for the intellegentsia--a pattern they found fruitful to follow elsewhere in Asia. Same with other tribal units in SE Asia, but many of them were more accessable to European (and the Japanese), and it was from them that insurgent forces were formed. Japanese presence in the Philippines goes back several hundred years. Maybe they'd have been able to maintain control over the harbors and a few of the key cities, but nobody actually has been able to control all the people who live there.

The Chinese themselves were divided between several anti-Japanese factions and Mao's revolutionary forces. It is unclear to me how they would have fared, had the Japanese not had their forces decimated by the US. Peanut perhaps still would have made it to Taiwan. Mao probably have endured, and eventually won control of certain areas--maybe even most--of China, but during that time the Japanese would still have had access to the resources of the north, and the Japanese presence may never have been successfully eliminated. It's certain that the Japanese would never have had an easy relationship with the eastern portions of China, but hey may have kept control of the rescources in Mongolia.

This leads to the interesting question of the Japanese relationship with the Soviets, perhaps yet another theme for a John Hershy novel. Pathetic attempts to solicit aid from the Soviets at the end of the war indicate that the Japanese would have been open to some sort of alliance after the spoils of the war were settled. Of course the Soviets cut them loose then, but in the alternate history, Japan would not have been the abject loser, and the Soviets would have...ah, well. Good thing the attacked Pearl Harbor, eh?

It's possible that the Japanese dream of Empire, though truncated, may have been realized. If they had been able to come to terms with Mao, they might even have had the idea to go to Taiwan, and reassert their claims to the island. With the help of the Chinese on the mainland, who knows if his new government would have stood.

Well. We got what we got. My parents met while working at a detention camp in Arizona: a bunch of German prisoners were held there. Many of them didn't want to go home after the war. I guess I might never have been born if the Japanese hadn't attacked Pearl Harbor. That's the short version.
posted by mule98J at 11:38 AM on January 25 [2 favorites]

>below the 100th parallel

Should that read "10th"? (Or "20th", which would cover the Philippines?)

Actually, it should read "past the 100th meridian". The Americans were worried about Japan invading Thailand. I got confused because they were, in fact, heading south to do it.
posted by valkyryn at 11:42 AM on January 25 [2 favorites]

Good stuff above. Counterfactual history as thought experiment is really not practiced by mainsteam academic historians. If you're going to ask the question, though, I think you need to separate Pearl Harbor the iconic event from Pearl Harbor as an aspect of a greater operational strategy. The choice faced by the Japanese brass was stark: full stand down in China or (from their PoV) eternal dependence on western colonial powers and suffering yet another indignity at Western hands.

Anything less makes war inevitable, because of all the reasons above plus one more: Japan's desire to create an asian hegemony ("Greater East Asia Co-Prosperity Sphere") basically could not allow the Phillippines to remain in American hands. It was, to paraphrase, the "dagger pointed at the heart of Japan."

An often overlooked stop on the route to war - and of Japanese war planning - was the bombing of the USS Panay. Which either (a) was an even early attempt to goad the US into war, (b) an attempt to convince the US that it was not worth maintaining a garrison in a warzone, or (c) to test the resolve of the US to direct attack.
posted by absalom at 1:45 PM on January 25

Add another voice to the 'it was going to happen anyway' crowd. Max Hastings' (very readable) account of Winston Churchill in WWII tracks the evolution of US entry in the war quite well, as it was Churchill's obsession. Having realised at a very early stage that US entry was the only route to victory in Europe, he was unswerving in his efforts to encourage belligerence and then full entry.

Anyway, from the Hastings book I took away that FDR was ultimately pro entry and expressed this as a moral imperative (e.g. his Four Freedoms speech in 1940). He was meeting with Churchill (sometime secretly), planning for all out war and slowly escalating the financial aid and other assistance to the allies (even extending the Lend Lease program to the Soviets) in 1940-41. Congress was lagging behind FDR, but still moving in a pro war direction.
posted by Albondiga at 2:58 PM on January 25

just a few corrections to one of the speculation posts:

It's worth noticing that American OSS operatives and British Commando forces were put in place to help organize guerrilla counterinsurgents in such places as Burma, Thailand, and Indo-China. Without our help, the local forces had little in the way of resources or organization to deal with the Japanese.

This maybe a little misleading. If you're talking about Stilwell's Chindits or Merrill's Marauders, those were less about starting up local resistance movements and more about inserting Western combat forces who were supported by local guides and communities. It was a very different operation from, say, what SOE and OSS did with organizing European resistance cells.

Even so, at least in the early days of the war, not all countries in southern Asia were equally disenchanted with the Japanese theory of booting out European influence over their internal affairs.

most of the occupied Asian nations may have been sympathetic to Japan's anti colonial message, but they were swiftly disenchanted with the equally racist attitudes that most Japanese occupiers brought to their dominions. Consider the success that the Germans had with attaining volunteers from fascist sympathizers amongst the French, Czechs or Norwegians versus the utter lack of foreign volunteers amongst Japanese forces (With the exception of, say, the figurative Indian National Army that was recruited to be an anti-British force. Your statement is overly optimistic towards the Japanese reception from their occupiers.

Japanese presence in the Philippines goes back several hundred years. Maybe they'd have been able to maintain control over the harbors and a few of the key cities, but nobody actually has been able to control all the people who live there.

Japanese presence? What? Compared to the Chinese communities who've made up a significant portion of the merchant class and were automatically anti-Japanese given their atrociities on the Chinese mainland? This is statement needs a significant amount of support to be taken seriously. The only way that the Japanese would have held the Philippines is through constant and brutal oppression, as they had during the war.
posted by bl1nk at 3:29 PM on January 25

Having realised at a very early stage that US entry was the only route to victory in Europe

Well, the only route to victory that didn't come several years "late" and at the head of the Red Army. Which, to Churchill, was just as bad of an outcome as Naziism, the die hard anti-communist he was. And, I suspect he might have suspected that whatever territory the Red Army occupied the Red Army was gonna keep.
posted by absalom at 3:37 PM on January 25 [2 favorites]

The only way that the Japanese would have held the Philippines is through constant and brutal oppression, as they had during the war.

It's always good to remember that over a similar time period, Americans committed similar atrocities.
posted by KokuRyu at 5:52 PM on January 25 [1 favorite]

n July 1941, the US imposed a full-scale embargo upon Japan, including all oil exports. This was highly provocative, and everyone knew it.

Absolutely. We were at the Pearl Harbor memorial in Oahu earlier this month. This was the thing that I took away more than anything else. Previously, I'd thought that was moving the Pacific fleet to the Pearl was more of a driver.

If you haven't been to the memorial and the museums, I highly recommend it. It does a better than expected job of setting the international context.
posted by 26.2 at 6:55 PM on January 25

blink: I agree.

Point 1.: Nuance is required regarding the operations in southern Asia. Stilwell and Merrell weren't trying to organize any local resistance to the Japanese. OSS operatives were few, and mostly focused on Indo-China. On the other hand, Americans and British soldiers killing Japanese oppressors didn't go unnoticed, or unsupported by the respective inhabitants. This was not a homogeneous activity. Some villagers were not happy to see the conflict erupt between the Japanese and Western forces, while others cheered our efforts on. A very few of these isolated areas were inhabited by tribal units with any nationalistic yearnings.

Point 2.: Most countries in Asia were thinking about shucking off the colonial powers when they were approached by the Japanese, and I agree that they all were quickly disenchanted, but this didn't happen all at once.

Point 3.: Although (before Taisho) Japan never had a significant naval presence overseas, Japanese and Okinawan traders had been visiting the Philippines for quite a while, but these visits were suspended during the Tokugawa era. I also agree, that the Japanese would have had a hard time maintaining a presence there. I guess my thoughts about this were that, without American intervention, there and elsewhere in the Pacific, they would not have been so easily expelled. It's possible, though, that they may have been able to co-opt certain wealthy Filipinos into supporting them, in order to retain control of their plantations. Collaborators always were frowned upon by the general population (and mistreated accordingly), and they may have relied upon the Japanese to provide them with postions of power and insulated them. This was a pattern during the Spanish era, and during the American era, when we were killing them off in numbers that defy one's imagination.

By the way, I'm happy to revise any of these musings in favor of any cohesive plot line. I would like to see a story that had the Samurai devolve into a caste of perfume-sniffing bean counters (with Hirohito--better yet, Sato--as the Shining Prince), and where the Yakuza took themselves seriously as defenders of the downtrodden. Then, when they send diplomats to Asia, the aspiring nationalists in all those countries could have formed an Asian Union out of the Coprosperity Sphere, similar to what happened in Europe as a result of the Marshall Plan. We could have a poignant chapter where all the white Australians are sent back to England. The new Boat People are not all welcomed there, and some of them have to come ashore in Miami.

Meanwhile, back in the USSA, our WPA projects will have given us first-rate bridges and highways, and we'd not have to spend much money on navies and air forces and so on. Norman Rockwell was appointed Secretary of War, and Curtis LeMay was appointed by President Bogart to be Secretary of Health, Education & Welfare. Naturally a whole genre of action movies will never have existed, so that platoon of actors will have been relegated to pumping gas and jerking fries out of the boiling grease. Pete Seeger, our Att'y General, makes short work of the oligarchs, and stamps out those union bosses who abuse the trust invested in them by the members.

I'm kind of liking this.
posted by mule98J at 10:46 AM on January 26 [1 favorite]

Not sure about the Philippines, but Japan had the lovely practice of Karayuki, sending women (typically from rural areas) to live overseas as indentured prostitutes.
posted by KokuRyu at 2:03 PM on January 26 [1 favorite]