Is That Legal?

Kinda. The problem is that these warnings were followed. The military leaders anticipated attacks by subs as well as sabotage. As a result they did things like concentrating all the aircraft on the island in well guarded areas and docking all the major warships in well protected areas. However, this just made them that much more vulnerable to air attack.

I'm not an expert, but documents from the Pearl Harbor attack hearings (http://www.ibiblio.org/pha/pha/extra.html)

A letter dated 24 Jan, 1941 from the Secretary of War to the Secretary of the Navy:

"MY DEAR MR. SECRETARY: The security of the U. S. Pacific Fleet while in Pearl Harbor, and of the Pearl Harbor Naval Base itself, has been under renewed study by the Navy Department and forces afloat for the past several weeks. This reexamination has been, in part, prompted by the increased gravity of the situation with respect to Japan, and by reports from abroad of successful bombing and torpedo plane attacks on ships while in bases. If war eventuates with Japan, it is believed easily possible that hostilities would be initiated by a surprise attack upon the Fleet or the Naval Base at Pearl Harbor."

The Joint Congressional hearings also point out a letter from Admirals Richardson and Kimmel on January 25, 1941:

"(a) United States is at war with Germany and Italy; (b) war with Japan imminent; (c) Japan may attack without warning, and these attacks may
take any form_even to attacks by Japanese ships flying German or Italian flags or by submarines, under a doubtful presumption that they may be
considered German or Italian; and (d) Japanese attacks may be expected against shipping, outlying positions, or naval units. Surprise raids on Pearl Harbor, or attempts to block the channel are possible. "

There's a Martin-Bellinger estimate which states:

"(a) A declaration of war might be preceded by:
"1. A surprise submarine attack on ships in the operating area.
"2. A surprise attack on OAHU including ships and installations in Pearl Harbor.
"3. A combination of these two."

Interestingly enough, while reports immediately post-attack seemed very interested in putting a great deal of blame on a 'highly effective fifth column' drawn from the surrounding Japanese-American population, the Congressional hearings held after the war indicated:

There is evidence before the committee, however, which reveals several salient considerations indicating that Japanese Hawaiian espionage was
not particularly effective and that from this standpoint there was nothing unusual about the Hawaiian situation. It is clear beyond
reasonable doubt that superior Japanese intelligence had nothing whatever to do with the decision to attack Pearl Harbor.

...and did they see it coming and do nothing (ie - "...Roosevelt very much wanted Japan to strike the first blow...")

Makes one wonder if the twisted logic (and ideology) that spews from the White House today could take the form of wanting Bin Laden to strike first. After all, war is good business, and the end justifies the means.

Makes you want to go hmmmm.

Not really.

As a grad student I did some research in Joseph Grew's papers for a prof who couldn't come to the archives. Grew was US Ambassador to Japan through most of the 1930s, up to the opening of hostilities. One paper that I found from about 1939 (if I remember correctly; that wasn't the target of the research) said quite plainly that if hostilities were to begin, Pearl Harbor would be the mostly likely place for a Japanese first strike. There were a number of people who had made similar determinations, and public Japanese discussions of conflict scenarios often included Hawai'i. (John Stephan's Hawai'i Under the Rising Sun has a lot of detail on these plans)

This letter doesn't offer anything like concrete intelligence that would alter the general plans being made. By this point, as you say, the administration was prepared to be struck, though Pearl Harbor did (apparently; there's some dispute) come as something of a surprise, because they mostly expected the Philipines to be the first target.

That particular letter isn't cited in the Pearl Harbor related histories I have on my shelf, but that's only a very small sample of the scholarship on the subject.

Snead16, yes, there is no doubt in my mind that GWB was looking for an "in." As soon as the rhetoric started, I firmly believed -- felt sure, in fact -- that there was nothing in the world Saddam could do to keep us from attacking (except, maybe, flying to D.C. and surrendering to American authorities). It was frustrating as hell to watch.

eric -- drop a line next time you're in town! or is this because i never got back to you for that interview....

I think it's more than the WWII equivalent of the Bin Laden security briefing -- as far as I know, the latter did not mention the location of the possible attack.

No, it's less.

As I said above, this is not "intelligence" but opinion, and not even particularly new or interesting opinion, at that.

The most significant difference between Pearl Harbor and 9/11 probably is that Roosevelt et al. knew that there was a significant chance that the negotiations were going to lead to open conflict (or, to put it more precisely, US involvement in ongoing conflicts in which the US had substantial but underappreciated moral and economic interests) and were prepared (not perfectly, but substantially) for that contingency and responded appropriately.

I leave the contrast as an exercise for the reader.

"Now I do know..."
"It seems settled that..."

As one who lived through the recriminations after Pearl Harbor, I need to tell you that a "cottage industry" prospered over the next twenty years or so, producing books which accused President Roosevelt of knowing that the attack was coming, of wanting an attack so we could be taken into the war, etc. Because of the general opposition to Roosevelt among the well-to-do and economically powerful, such books received attention in the press, were heavily promoted to the public and (as Gingrich later said) "conservative books sell". In the last four years of the present administration, the effect has worked the other way, so far.
Certainly the most likely conclusion regarding both events is that many people failed to do the needed thinking.

I think snead16 hit it on the head - the relevant point was that even though we had carriers, we didn't really think of carrier-borne aircraft as a threat on the same order as subs or battleships.

My (high school level) understanding is that the US Navy as a while didn't really appreciate air power until Midway.

The Navy had been experimenting with carrier strike attack scenarios for at least a few years, so they had some inkling of the power of the technology in which they had invested considerable energy and money.

Midway was, I'd say, more of a symptom than a cause of the rising general awareness of the value of air power projection.

Thanks for the link. I could also add that Italian frogmen and "human torpedos," midget subs, did a great deal of damage to the British Mediterranean Fleet. Clearly the Japanese were paying much closer attention than the U.S. to events in that theater.

Welll...

The big thing to watch for would have been the British raid at Taranto, where the Royal Navy attacked the Italian fleet at anchor in a surprise raid. (November, 1940) This raid was, in fact, studied by Japanese staff planners for the Pearl Harbor attack.

While this raid was examined by the Pearl Harbor commanders, the conclusion was that the harbor's depth was shallow enough that torpedo attack was unlikely, and that deploying torpedo nets would cause a great deal of harbor congestion.

The really strange thing is that US Naval planners not only predicted that a raid conducted by torpedo and dive bombers might precede a Japanese declaration of war, but that dawn would be an ideal time! For some reason, however, General Short decided to focus mainly on the threat of sabotage, which was assumed because of the large Japanese-American population, thinking that the Navy would conduct any long-range reconissance necessary to detect a Japanese attack. The Navy, on the other hand, had decided that running long-range reconissance would have been too costly in terms of wear on men and equipment.

So essentially, Pearl Harbor was more like having had a bunch of reports saying that if a certain strength hurricane hit New Orleans, a lot of people would be in trouble. Then not doing anything even though a hurricane of that strength was on its way and about to hit...

Before Billy Mitchell was courtmartialed for insubordination.

"Following a trip to Japan early in 1924, Mitchell submitted a report which has been labeled 'the masterpiece of his career.' In it, he foretold of Japanese expansionist ambitions in the Pacific and presented what he considered would be the start of a Pacific war. Basically, he stated such a war would start with a Japanese air and sea attack upon Pearl Harbor in Hawaii with an accompanying aerial attack on the Philippines:

'Attack will be launched as follows:

'Bombardment, attack to be made on Ford Island (Hawaii) at 7:30 A.M..... Attack to be made on Clark Field at 10:40 A.M.' "

It's hard not to be astonished at the Navy's complacency in December 1941. Admiral Kimmel's predecessor, Admiral Joseph Richardson, had gone to the mat and lost his job because of his opposition to transferring the fleet from San Diego to Hawaii -- where he believed it would be too vulnerable. A series of fleet exercises in the 1930s had amply demonstrated the ability of carriers to conduct a surprise attack from unexpected directions. Experts were aware that the surprise attack was a major part of the Japanese military tradition, and such an attack on the enemy's main fleet base had opened Japan's last major war in 1904. It's hard to believe the US Navy dismissed the significance of Taranto based on the shallow water depth in Pearl Harbor. All things considered, Kimmel deserved the blame he got.

Re. the August 6th 2001 PDB, this was not "actionable intelligence." It was a typical scattershot CIA product -- we think al-Qaeda is planning an attack in the US but we don't know where or when, and the FBI is on the case. Much as I might wish to lay some blame on the President and Condi Rice, we have to give them a pass on this one.

If DOD's Don Rumsfeld had his way, the U.S. Navy would have FEWER operational aircraft carriers today than it had on that fateful morning of December 7, 1941. One recommendation during the DOD's 2001 Quadrennial Defense Review was to reduce the Navy's aircraft carrier force from 12 to 6!

As horrifying as the events of 9/11/01 were, had the terrorists instead struck after such a reduction of our naval airstrike capability, the results would have been even more catastrophic and our military response would have been severly compromised.

It is also known that the terrorists scouted the San Diego Naval Base. Imagine had they succeeded in sinking a carrier in a suicide attack (Lindberg Field is just seconds away)? Remember, their original plan called for hijacking airliners on both coasts.

Congress needs to demand that Rumsfeld scrap his foolhardy policies. Instead of decreasing the size of the fleet, we should be increasing it, less we run the risk of suffering a 'third' Pearl Harbor.