Spain, portugal, and turkey join the axis. The axis invade switzerland. The allies are, for whatever reason, unable to successfully invade continental europe. The soviets are able to sweep over europe & annihilate the european axis.
The japanese press into china, India, Australia, & the pacific. The japanese empire is stretched to thin & most of it (China, India, Korea, Indonesia, & the japanese home islands) is seized by the USSR.
The soviets create a series of satellite states out of its conquered territories.
Also, for the sake of the scenario, lets say the CCCP is lead by a ruler more traditionally communist, like trotsky, or a surviving lenin.
What would happen afterwards?
(Not very realistic, I know, but I think it would have been interesting)