Even assuming a plausible scenario in which the US couldn't defeat Germany, that doesn't have anything to do with whether we could have defeated Japan standing alone.
Historically, we know it wasn't that hard for the US - despite Japan attacking first, the US adopted a "Europe First" strategy that committed approx. 2/3 of capacity to fighting Germany. Despite this, the US defeated Japan easily - there are no major victories for Japan against the US after Pearl Harbor, and Midway was less than a year after Pearl Harbor. If the US strategy is "Japan First" (doing things like transferring the Atlantic Fleet to the Pacific), why should we expect the Pacific war would last long enough that Germany would be able to consolidate a victory in the east into driving the UK into peace and be able to intervene in the Pacific?
Also, why do you think an invasion of Hawaii was possible? The surprise strike was at the end of Japanese logistical capacity - I think the US wins if Japan tries a land invasion.
If the US strategy is "Japan First" (doing things like transferring the Atlantic Fleet to the Pacific), why should we expect the Pacific war would last long enough that Germany would be able to consolidate a victory in the east into driving the UK into peace and be able to intervene in the Pacific?
Remember the context: we are in the hypothetical where all US ships (Atlantic fleet included) were magically anihilated in the end of 1941.
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!