But, as I said, I'm new here, so I wonder if anyone knows what the political ramifications might be if the US declared war due to Japan seizing the Dutch East Indies. I recall there being a substantial isolationist sentiment in America after WWI; the surprise attack on Pearl Harbor mostly silenced the nay-sayers, but how would it go down if there was no sense of betrayal, no sneak attack directly against U.S. forces to force Congress' hand?
It won't be directly because of that. It will be because of a later
casus belli. The US doesn't want to leap to the defence of a colonial power; however, it will trumpet things like "freedom of navigation" while sending the Navy steaming around inviting trouble, and either use a later outrage in China (which is a US interest) or an actual attack on a US-flagged ship (which is pretty much guaranteed somewhere along the way) to justify entry into the war.
The US doesn't actually want to go to war
yet. Every day that passes it gets stronger relative to Japan - the various US war plans always envisaged a 1-2 year buildup of overwhelming force, during which time the Philippines would fall, and then launching a campaign to take everything back. But it
does want to go to war. Well, regime change that left Japan introverted and isolationist and not intervening in China would do. As long as isolationist doesn't involve any trade barriers to US companies seeking to do business there. Anyway, once Vinson gets the navy funding through Congress, it's just a matter of waiting until the correlation of forces tilts inexorably in the direction of the US.
Your answer does a fantastic job of answering why Japan perceived a preemptive strike against the USA as necessary to securing the supplies it needed to continue its own war efforts, but I wonder how they might have acted if their ambassador had his finger a bit more on the pulse of US opinion re: foreign policy.
To some extent it was an accurate assessment - the US establishment's position identified Japan as a competitor for commerce and influence in the Pacific, to be defeated and preferably turned into a client state. It just wasn't committed to spending the money to do so militarily before June 1940, and wasn't prepared politically to spend the blood to do so in December 1941 when the choice was taken away from Roosevelt. In terms of identifying the influences on US policy, for instance, SecWar Stimson was one of the members of the Price Committee, which was one of the China Lobby pressure groups that had been pushing for support to Chiang since 1937.
Without the Pearl attack, the invasion of the Philippines (which were, at the time, a close US ally and in effect a colony) is played up the same way.
Yes, this too.
Japanese naval strategy was an extension of Mahan's - destroy the enemy fleet with a decisive battle and then attrite their economy and army by strangling their commerce with a blockade. The
Japanese version accepted that the disparity in battleship forces (the Washington Naval Treaties had set the US, UK, and Japan at 5:5:3 tonnages respectively) required an additional phase to the campaign to degrade the enemy battle line before the final engagement. The
kantai kessen approach was broadly:
- Capture the Philippines
- Taunt the Americans about their maternal odours and rodent parentage
- When the USN obligingly sails its battleships to Manila, use a combination of submarines, night-time destroyer torpedo attacks, and air strikes from both carriers and land-based bombers to whittle down the opposing force, until it turns up weak enough to be sunk by the mighty battlewagons of the IJN.
- Accept the inevitable armistice from the weak-willed Americans and be back in Kure in time for tea and medals.
I oversimplify, of course, but not
that much. Yamamoto didn't really think it would work, as he added up two and two to get
the squadrons of carrier planes will blot out the sun and while he was happy to fight in the shade, did bear in mind what the historical outcome was for Leonidas no matter how brave his rhetoric. Seeing the opportunity to sink the enemy battlefleet straight away, he seized it rather than waiting for the later decisive battle.
US strategy was a similar approach approach, kind of, except that it involved putting troops and airfields on all the islands between Hawaii and Luzon and fielding huge numbers of escorts (at Leyte Gulf, the USN had more ships than the Japanese had
aircraft) to ensure that the fleet advanced largely untroubled by pesky little air raids, nighttime surface actions, or submarines, at which point the massive advantage in weight of metal would mean that the opposing force would be weak enough to be sunk by the mighty battlewagons of the USN. Along the way it would evolve to make that "by the mighty carrier air groups of the USN", but it's the thought that counts.
@Magnum: a lot of the US establishment is looking to take Japan down a peg or two.. or all pegs, really. Everybody expects that war is coming; they are not even all wrong about how easy it will be. Letting Japan get hold of DEI oil and Malayan rubber (and the income therefrom) is guaranteeing a further trouble in China because Japan will then be able to carry on its war there.