ORIGINAL: brian brian
It's not what the USA can do in 1941 that matters. It's how much combat power they will have in 1944 and 1945 when they will squash Japan like a bug. Will Japan get enough Return On Investment - expand far enough and build enough forces - to resist that? That is the essential decision for Japan in the game. Japan has powerful forces at start - amphibious units when no one else has them, strong fleet carriers, good ground units, and can do whatever it wants against any enemy it selects. The 2 long-range Zeroes that can be built in 1940 are strong assets as well.
You should explore the question however you wish though.
I always find the hardest decision when playing World in Flames solitaire is how Russia and Japan will interact.
You are right, the return on investment won't be good enough. The initial +2 oil will soon disappear as the US entry options kick into place that much quicker and the embargoes start. The US is then gearing up that much quicker and a shed load of nastiness hits the Axis that much earlier.
In Tokyo, the hot-heads from Military Planning are summoned to the Emperor. The first draft of their war-plans has been overseen by two wise and learned masters of the mysterious and subtle arts of putting a world in flames. Orm-San and Brian Brian-San politely pronounce the designs "Brave" and "Naively optimistic" and it's back to the drawing board.
Meanwhile the initial demands of the war are upon them. What actions to take?
Germany land, Italy combined. With the USSR looking like it might DoW, the Japanese choose naval to get some escorts in place in case the subs sortie.
No port attacks or naval air.
