Japan invading Russia, they would have to cross thousands of miles of before they got at the heart of Russia.
However not attack at Pearl Harbour would allowed Japan to dominate all of East Asia towards India and down to Australia and that would have made Japan a very powerful country in the end.
They whole point is, if Japan and especially Germany were able to fight for a longer peroid of time and attack areas away from thier factories and such, they would have become stronger and Germany would have developed nukes.
America for certain would have gotten in WW2 after Britan had fell. However, they would have a had hell of a time facing Germany a lone and then if the Japanese got involved who are more powerful by dominating eastern Asia...
It would have been totally different.
