Pretty much everybody knew a war was coming. (Which was one reason why it makes no sense to say Roosevelt or Churchill would have concealed information about Pearl Harbor - assuming they were looking for a war, they already had gotten what they wanted.) But the Americans assumed that the Japanese would attack in the west Pacific - the Philipines, Guam, Hong Kong, South-East Asia, the East Indies. An attack across the ocean at Hawaii was generally considered to be beyond Japanese capabilities.
You cite a sentence that says that Hitler, who knew more about Japanese plans and capabilities than the US, thought it was impossible but that we were supposed to take the idea seriously? This seems contradictory in the extreme.
You cite a sentence that says that Hitler, who knew more about Japanese plans and capabilities than the US, thought it was impossible but that we were supposed to take the idea seriously? This seems contradictory in the extreme.
Such attacks would have to be launched from aircraft carriers but before this could be done, the Japanese must first wipe out American naval units in the Pacific and including bases in Hawaii and on the western American coastline.
I don’t read it like that, I read it as ‘the first targets would have to be Hawaii and the western American coastline’
- a rather different interpretation
To be honest, I doubt that Roosevelt knew but I would be surprized if he did not consider it likely.
Look, even if you think that FDR wanted a an excuse to go to war with Japan, you have to acknowledge that he also wanted to WIN that war. And Pearl Harbor was such a disaster, it nearly made winning the war impossible.
He MAY have wanted the Japanese to commit some kind of act that would justify a declaration of war- but he did NOT want the Pacific fleet at the bottom of the ocean!
There are a lot of details missing in this analysis (which in broad terms seems to me to be very much on target so far).
If you think U.S. opinion is divided today, this is nothing compared to 1940-41, up through December 6th. While everyone was well aware that Hitler’s Germany was in the process to taking over Europe, that was 3,000 miles away, across an ocean – and transatlantic voyages and flights were major undertakings at the time.
Japan’s expansionistic aspirations were well known to the U.S. And our strategic goals required that we be in opposition to them. (E.g., Guam was surrounded by Japan’s post-WWI mandate; the Philippines were a resource-rich U.S. commonwealth that effectively bordered Japanese territory; U.S. interests in China were threatened by Japanese advances there.)
Roosevelt was well aware that sooner or later we would need to fight both Germany and Japan if somebody else didn’t stop them first – that was why he was so strongly supportive of France (before its Fall), the U.K., the U.S.S.R., and KMT China. It was hoped that they would win the war, with our aid given in armaments and exported goods, through Lend-Lease and other programs, instead of our being drawn into it. That was Plan A; our intervention in the war was Plan B, if Plan A failed. It took a combination of American production and manpower, Soviet manpower and tenacity, and British/dominions determination to defeat the Axis; if we had remained completely isolationist while Britain and Russia fell, we would have had it tough to combat the victorious Reich and Japan.
It was Secretary of the Interior Harold Ickes, with Roosevelt’s tacit consent, who imposed the export bans on scrap metal and oil to Japan that brought things to a head.
As negotiations with Japan failed in Washington (understandably – Japan asked the unacceptable; so did we; and nobody was willing to budge), we were well aware that Japan would launch an attack. And Pearl Harbor and Manila were notified of this. But the precautions that both took were against sabotage, not aerial attack – expecting Japanese nationals in Hawaii and Luzon to attempt subversive efforts to damage strategic resources. As a result, we were perfectly positioned to repel saboteurs that didn’t attack, and perfectly set up for the major damage wrought by the real attacks.
There’s a very thorough study of whether there was any validity to the conspiracy theories, commissioned by the Republican Congress of 1946 – and it found no evidence of any.

In fact, I’d say it’d be easier to prove that if we’d have gotten involved sooner, it would have been better for all parties involved.)
I’m not sure I agree about that.
The US military of the late thirties was probably as obsolete as the Polish Army of 1939. The build up of the Navy was just beginning, against huge resistance. The Air Corps was still wedded to the “Flying Fortress” concept, and actively resisting looking to the signs that it wasn’t going to work the way they expected. The Army still viewed the role for tanks as being one of support for cavalry recon.
All these things started changing quickly after 1939, but there were all sorts of delays between recognizing the need to change what the military had, and actually starting to produce the needed materiel. Just look at the Grant/Lee tanks of the Africa Campaigns for an example of some of the kludged together systems that had to be used, because what the military had was inadequate - and they didn’t have time to make anything better.
Can someone give me the bullet points of this stuff, because I have a freind that feels the same way. I just think the whole thing is illogical. You may as well blame Bush for 9/11.
There is a Wiki article on this, Pearl Harbor advance-knowledge debate that serves as something as close to bullet points as you can get.
That article also notes that there were nine investigations of Pearl Harbor.
And still Robert Stinnett was able to use the FOIA to gain new material for his Day of Deceit, which led to even more digging through the files.
None of this has ever provided a single “smoking gun.” Just the opposite. We know for sure that give-away Japanese communications were not decrypted in time. Most of the case for a conspiracy is necessarily of the circumstantial evidence variety. It is a pattern of small things that are hard to explain, and of actions not taken.
But the larger pattern of actions that were taken are almost impossible to square with a conspiracy. It’s hard enough to explain peoples’ actions at the best of times. Trying to explain why people took the actions they did if they knew ahead of time that the attack was coming is brain-busting. It’s simply not good enough to detail small things if you can’t account for the very big ones.
Roosevelt was preparing to go to war with Germany. He was aware of Japan as a threat, but his attention was focused on Europe. The last thing he wanted was to divert the country’s anger and resources toward Japan. Remember, if Germany had not declared war on the U.S., we would have been unlikely to do so with an isolationist Congress furious at the Japanese. Any conspiracy theory has to account for this. Europe was always the real target. Asia was a distant and unwelcome second. That alone is enough to sink conspiracy theories for me.
@Exapno
Well, the Asian and European sectors were not exactly separated, the USSR had memories of 1905 and were very worried about the Soviet Far East.
Pulling the Japanese off the USSR allowed them to concentrate on stuffing the German advance. I’ve read that the victory at Moscow was down to Winter trained troops from Siberia who had been held back because of worries about the Japanese.
From the German point of view the USA was already at war in Europe, from the Japanese point of view the USA had put them in an impossible situation. With hindsight the attack on Pearl Harbour was a failure, but a pre-emptive knee in the groin is quite an effective tactic.
Thinking about it, I don’t think that the British would have wanted to be seen withholding intelligence from the USA, but they might have timed things carefully. Perhaps the easiest thing to do is to dismiss Pearl Harbour as a cunning British ploy to get the USA involved on a total war basis - being British and being brought up by those who were involved at the time, it is the way my mind works. Tell them enough to reduce the damage, but not enough to allow them to avoid full mobilization.
Like dropping hints, but saying ‘I’m not sure but …’
As long as we’re on the subject, there’s also a lesser known conspiracy theory that the United States government had a hand in Germany’s declaration of war.
The Department of War had developed a plan of a massive military build-up in 1941. It was commonly known as the Wiedermeyer Plan after its principal author, General Albert Wiedermeyer. It was based on the premise that Germany and Japan would successfully conquer Europe, Asia, and Africa and the Americas would be on their own. The plan called for a massive build-up of American military industry, the formation of a massive army, and then an attack on Germany, with Japan to follow after Germany’s defeat. (Obviously, a lot of this plan ended up being used in the actual war.)
The plan was supposed to be top secret but a copy of it was inexplicably leaked to the Chicago Tribune, a strongly anti-Democrat and pro-isolation paper that had been accusing Roosevelt of trying to drag the United States into the war. The Wiedermeyer Plan seemed to confirm everything they had been saying and the paper published it shortly before the Pearl Harbor attack.
Germany obviously read of the American plans to build up its military and then attack Germany. When Japan bombed Pearl Harbor, Hitler reasoned that conflict with the United States was inevitable and declared war.
The thing is nobody to this day knows the identity of who leaked the Wiedermeyer Plan. It’s generally assumed that it most have been some isolationist in the military. Some people even speculated it was Albert Wiedermeyer himself (although he denied it and said he wouldn’t have revealed classified information).
But others later speculated that it might have been leaked from within the White House. Many people have noted that Hitler did Roosevelt a favor by declaring war on the United States. The American people and Congress were united against Japan after Pearl Harbor, but there were still people who would have opposed an American declaration of war against Germany as well. So some people have speculated that Roosevelt might have leaked the plans to provoke Hitler. Of course, this theory also assumes Roosevelt was aware of the impending Japanese attack because the plan was leaked before that.
Little Nemo, sounds like an interesting conspiracy theory, and one that doesn’t trigger most of my usual bs warnings. It sounds like a credible act, and one I could see having been done.
But wouldn’t this plan have been old news, simply confirmation of intent, considering that the Atlantic Conference (Agreed to and published in August of 1941) was public knowledge at the time?
It seems like whenever some sort of notorious attack takes place, there are people who claim that it was a Reichstag sort of event. Ask for your friend’s opinion about the OKC bombing (was it really the UN/Clinton?); the 9/11 attacks (was it really the Israelis?); Iraq’s invasion of Kuwait (did the USA invite Saddham to attack?) etc.
This sort of people are really not receptive to facts that contradict their ideas. Conspiracy theories are ‘cool’ and always have that ironic ‘great misinformation conspiracy’ argument that normal people are lied to constantly about history. It’s fun to have something that sets you apart from other people, though the spread of it is certainly annoying.
But wouldn’t this plan have been old news, simply confirmation of intent, considering that the Atlantic Conference (Agreed to and published in August of 1941) was public knowledge at the time?
The Atlantic Conference made no mention of any American plans for entering the war.
This sort of people are really not receptive to facts that contradict their ideas. Conspiracy theories are ‘cool’ and always have that ironic ‘great misinformation conspiracy’ argument that normal people are lied to constantly about history. It’s fun to have something that sets you apart from other people, though the spread of it is certainly annoying.
I agree. I think one of the attractions is that conspiracy theories give a person a short-cut to intellectual superiority. If two people are having a normal debate on some subject, part of the debate is going to be who has a better command of the facts regarding the issue. But a conspiracy theory gives you an advantage because you can start with the premise that whatever your opponent knows about the subject is wrong, so you obviosuly know more than him.
Little Nemo, sounds like an interesting conspiracy theory, and one that doesn’t trigger most of my usual bs warnings. It sounds like a credible act, and one I could see having been done.
The problem is that it requires the other theory - that Roosevelt knowingly ignored the Japanese attack on Pearl Harbor - in order to work.
There were a lot of people in 1941 who opposed Roosevelt because they felt he was pushing for a war. Personally, I don’t think he wanted a war - but he was certainly willing to go much farther in preparing for a war and risking the possibility of war than the American people or Congress were. If it had been discovered that his covert war plans were even more extreme than his known war plans, it would have been a political disaster for Roosevelt.
So when the Wiedermeyer Plan was published, it was initially just such a disaster. Isolationists and other anti-Roosevelt people were all condemning him and preparing for much more serious steps against him. And then the Japanese bombed Pearl Harbor and public opinion completely reversed. Roosevelt went from being a warmonger to being a genius. His opponents, especially those who had opposed military preparations, were completely discredited.
So everything worked out to Roosevelt’s great advantage (with the obvious exception that he still had a war to fight). But if the Japanese hadn’t attacked it would have been an equally large defeat for him. So the only way he would have released the Weidermeyer Plan would have been if he had been certain of the Japanese attack to follow. Which, for the reasons others have pointed out, is virtually impossible to believe. So it looks like Roosevelt’s luck was in fact just luck.

A guy at work often goes on about how the Americans allowed Japan to bomb Pearl Harbor as a trigger to get involved in the war. They needed a big bang to get public opinion on their side. I don’t know all the details but apparently many indicators of attack were deliberately ignored. Give me the straight dope so I can squash him the next time he brings it up.
Just because we missed a lot of indicators doesn’t mean we did it deliberately!
About this so-called “theory”, I always argue back like this:
Oh come on. Do really say that if Japan attacked us and we successfully repelled the attack, people wouldn’t have wanted to go to war? In other words, in order to get American support for the war, we had to start out by shooting ourselves in the foot!
If we really had been sure, then we would have kept everything quiet but prepared the fleet and the air forces so that we could at least fight back on an equal level.

Look, even if you think that FDR wanted a an excuse to go to war with Japan, you have to acknowledge that he also wanted to WIN that war. And Pearl Harbor was such a disaster, it nearly made winning the war impossible.
He MAY have wanted the Japanese to commit some kind of act that would justify a declaration of war- but he did NOT want the Pacific fleet at the bottom of the ocean!
And that argument right there says it all.
Well, the irony is that because the fleet was sunk in port, in shallow water, almost all the ships were recovered and used against the Japanese. If they had been deployed out at sea, they would have sunk and never been usable again. So we greatly benefited by not responding.
This, of course, sends conspirators’ hearts racing.
If they had been deployed out at sea, they would have sunk and never been usable again
… had they been all found and all sunk. It was a lot easier to do that while they were in port.
Here’s an opinion from the Naval Technical Board. It’s mainly about overall pacific fleet stragety, but does address deep water losses briefly at the end. Apparently, even if our fleet had been lost in deep water, we still would have had a powerful fleet by '45.
Imagine if we had lost the fleet over the Marianas Trench. The lost BB’s would have been replaced with Iowa class ships that were more powerful, more technically advanced (ie, better RADAR) and FASTER (33 knots or so). The IJN cleared out our old inventory to make room for the better stuff.
In losing the fleet at sea, the biggest loss would not have been the ships but the officers and crew. In that regard The attack on Pearl was in our favor as so many of the crews were not aboard ship or were able to be quickly rescued from the water by small harbor craft.