If anything, the U.S. would have been in a similar position, i.e. at war with Japan with guaranteed victory, even if every single ship under the U.S. flag magically got sunk on December 7, 1941.
This is suspect. The U.S. had greater industrial capacities and population than Japan, but that doesn't guarantee victory. Rebuilding the navy would take a lot of time which the Japanese could use to end their war in China. Also, it was far from clear in late 1941 whether the USSR would withstand the German assault and whether the British would not seek peace.
Even in the worst possible case, I still don't see what could prevent the U.S. from simply cranking out a new huge Pacific navy and overwhelming Japan. Yes, the production would take a few years to ramp up to full capacity, as it did in reality -- but once it did, I can't imagine what could save Japan from being overwhelmed.
Ending the war in China wouldn't have helped the Japanese at all, even if they linked with a victorious German army in the Far East. An additional land army at their disposal could not prevent the U.S. navy steamroller from eventually ...
I was very interested in the discussions and opinions that grew out of the last time this was played, but find digging through 800+ comments for a new game to start on the same thread annoying. I also don't want this game ruined by a potential sock puppet (whom ever it may be). So here's a non-sockpuppetiered Irrationality Game, if there's still interest. If there isn't, downvote to oblivion!
The original rules:
Enjoy!