Not a big expert on pre-war Pacific political geography, and was always skeptical of these kind of claims but ... General Marshall was called to a post-war Congressional inquiry -seven- times and always had to disappear abroad on urgent business of high import to United States foreign policy. He never appeared. Clearly, he was not going to answer any questions about the run-up to war and it is likely that the war with Japan was precipitated.
There was nothing wrong with that as an aim (unless our own interests were not at risk) but it does mitigate Japanese guilt for unprovoked aggression or other non-Convention ‘moral equivalency’ charge.
As far at the future goes, I do not think Japanese re-militarization would be of any significance, any more than German re-militarization. It is much much cheaper to purchase the land than it is conquer it. East Prussia would be like East Germany in that it is cost-center and not a profit-center. Economically it is worthless - to the German state. To those who lost their ancestral lands, it is priceless. But that is another matter.
Japan’s only remaining territorial claims are the Kuriles and this is not going to be settled militarily.
General Marshall did testify before Congress concerning the run-up to Pearl Harbor and the role of the Chief of Staff's office has been thoroughly researched. The vast majority of the focus has been on the question of whether warnings were adequate to the commands in Hawaii or whether action could have been taken to defend against the attack.
The argument over the embargo strikes me as classic appeasement reasoning. The embargo only came after years of Japanese war against China and clear threats against Southeast Asia. A policy to supply Japan's war effort against China and possibly others might have avoided the 1941 attack on Pearl and delayed a general war in Asia, but when it came Japan would have been stronger.
I agree. Re-militarization could help, actually, to deter the threats from China and a nuclear North Korea.
It is troubling, however, that the Japanese largely refuse to recognize the fact that their unjustified aggression caused the Pacific War, while in contrast Germany has faced its past and is determined not to repeat it. The situation in Asia today, however, is vastly different than in 1941 - Japan could never dominate Korea and China today as it could before WWII, even if became inclined to do so again.