elt177,
Yeah, Yamamoto was so against the war he threatened to resign if his plan to attack Pearl Harbor wasn't adopted.
Bill
Umm... I don't think you're being fair. He DIDN'T want to war against the US. He KNEW that Japan was lost in a long war with the US. However, given that the decision was made to go to war, he figured the only possible way to survive was to hit the US hard enough to make them back down, hence Pearl.
I think that Bill is being entirely fair. There was a need in Japan after WW2 for a tragic hero and Yamamoto was given the role in "The Relucant Admiral" etc. However, he may have been a contender for the worse admiral ever judging by his plans for Coral Sea, Midway etc. and I believe he was the only senior figure wanting to attack the USA by late 1941.
In the previous thread, I tried to ask about who wanted what in the Japanese Goverment in 1941. I have found a few extra quotations and sources since then.
Here is a long quote from Louis Morton's "Japan's Decision for War", chapter 4, pages 105-6:
"By the middle of August the two services had agreed on a broad line of strategy. The impetus came from a series of studies presented by the Total War Research Institute, a subordinate body of the Planning Board. Forecasting the course of events during the next six months, the Institute called for the invasion of the Netherlands Indies in November, followed the next month by surprise attacks on British and American possessions in the Far East. Anticipating that the United States and Great Britain would utilize Soviet bases in a war against Japan, the Institute's studies dealt with the problems of economic mobilization; military planning, except in the most general sense, was left to the services.
These studies, as well as others, were discussed heatedly during the tense days that followed the embargo. From these discussions emerged four alternative lines of strategy, all of them designed to accomplish the swift destruction of Allied forces in the Far last and the early seizure of the Netherlands Indies. The first was based on the Institute's studies and provided for the seizure of the Indies and then of the Philippines and Malaya. The second called for a step-by-step advance from the Philippines to Borneo, Java, Sumatra, and Malaya. The reverse, from Malaya to the Philippines, constituted a third line of action and one which would have the advantage of delaying attack against American territory. The fourth plan proposed at this time consisted of simultaneous attacks against the Philippines and Malaya followed by a rapid advance along both axes to the Indies. Admiral Yamamoto's plan for an attack against Pearl Harbor, work on which had begun in January, did not enter into the calculations of the planners at this time.
Army and Navy planners agreed that the first plan was too risky for it would leave Japanese forces exposed to attack from the Philippines and Malaya. The Navy preferred the second plan; it was safe, provided for a step-by-step advance, and created no serious problems. The Army objected to it, however, on the ground that by the time the main objectives in the Netherlands Indies and Malaya were reached the Allies would have had time to strengthen their defenses. The third plan, with its early seizure of Malaya and bypassing of the Philippines, appealed greatly to the Army planners who hoped in this way to gain southeast Asia and delay American entry into the war. But this course, as the Navy pointed out, also placed American naval and air forces in the Philippines in a strategic position athwart Japan's line of communication and constituted a risk of the utmost magnitude. The fourth course, simultaneous attacks and advance along two axes, created serious problems of co-ordination and timing and a dangerous dispersion of forces. But because it was the only course which compromised the views of both groups, it was finally adopted."
Thus it was the IJN rather than the IJA that demanded war with the USA. That leaves who in the IJN and why?
I found an article by Scott D. Sagan "The Origins of the Pacific War", Journal of Interdisciplinary History, Vol. 18, No. 4, The Origin and Prevention of Major Wars. (Spring, 1988), pp. 893-922. On page 913 this states:
In the Imperial Navy strong disagreements arose between the leading members of the Navy General Staff and Admiral Yamanoto Isoroku, Commander in Chief of the Combined Fleet, who had created a new operational plan for a surprise attack on the Pearl Harbor fleet. Vice Admiral Kondo Nobutake, for example, maintained that Japan should attack Malaya and the Dutch East Indies only, and numerous high-ranking officers opposed the Pearl Harbor plan. ....Yamamoto, who favored concessions to avoid war, nonetheless argued that a surprise attack against the United States in Hawaii and the Philippines was preferable to awaiting American actions because "we cannot rule out the possibility that the enemy could dare to launch an attack upon our homeland to burn down our capital and other cities."
Yamamoto's view seems to go back to a "war game" in November 1940 carried out by the Combined Fleet staff under Yamamoto (Sadao Asada, From Mahan to Pearl Harbor, page 279) which concluded that an attack on the Netherland East Indies would lead to war with America. I don't understand how or why the Combined Fleet was making that decision rather than the Foreign Ministry, the Navy Ministry or the General Staff. However, it has been noted that as early as February 3rd 1940, Yamamoto had asked Captain Kanji Ogawa of Naval Intelligence to start intelligence gathering on Pearl Harbor.
I had posted that "The Shattered Sword" by Jonathan Parshall and Anthony Tully suggests on page 24 that the Chief of the General Staff, Nagano Osami, did not wish to attack America. Morton also backs Shattered Sword's view of Nagano "There was only enough oil, Admiral Osami Nagano told the Emperor, to maintain the fleet under war conditions for one and a half years and he was doubtful that Japan could win a "sweeping victory" in that time. His advice, therefore, was to drop the Tripartite Pact and reach agreement with the United States."
I found some more quotes in "War Leadership Concept before the Greater East Asia War: Aftermath of the Imperial National Defense Policy" by Taeru Kurono:
1. On July 31, 1941, upon inquiry by the Emperor concerning the possible war against the United States, Osami Nagano, Chief of the Naval General Staff, replied to the throne that it was doubtful whether Japan could win, not to speak of achieving a great victory as won in the Battle of the Sea of Japan, and if it prolonged, he “had no idea about the consequences,” and the Emperor entertained the impression that “how dare we start a war with no prospects of victory.”
2. On November 4 1941, Nagano stated, “I am certain that the Imperial Japanese Navy will be victorious for the first two years, but I cannot foresee what will happen if the war becomes prolonged because the future holds various uncertain factors.”
3. However, on July 21, Nagano announced that Japan should decide to start the war against the United States promptly because the differences in the military strength of Japan and the United States would enlarge as time passed (Sawamoto Yorio's Diary, entry on July 21, 1941).
As mentioned in the previous thread, the Navy Minister, Shimada Shigetaro, is reported by Fukudome Shigeru to have opposed attacking America (The Japanese Navy in World War II, ed. David C. Evans, page 6). I also mentioned that Rear-Adm. Maeda Minoru, head of General Staff Intelligence Bureau, believed that operations in the East Indies would inevitably lead to war with the USA (interview, 19 June 1962, Boeicho Senshibu Archives), with the argument was that the Europeans and Americans were the same race.
I can't name names offhand, & I"m not sure if any were actually named, but that was the conclusion Peattie & Evans came to in Kaigun. It's my suspicion, nothing more really, IJN was using it as a lever on IJA a) for budget reasons, b) to dissuade them from attacking DEI, or c) both.
I think that pacifichistorian was correct in his suspicions for 1940 (alas that he cannot tell us what he has found since

). However, it was only Yamamoto who wanted the Pearl Harbor attack by late 1941.