There are hundreds of stories out there of every kind about an alternate WW2 that leaves a Reich-dominated Europe up to the Urals, a massive Japanese Empire in Asia and the Pacific, and an America occupied and/or annexed and/or balkanised by the Krauts and/or Japs. Examples include Man in the High Castle, In the Presence of Mine Enemies, etc.
But whenever a realistic scenario is tryed to work out here, the concessions are huge. Japan is almost always thrown under the bus, Russia is still very much alive behind their Ural or even Brest-Litvosk borders, Germany has no colonial empire and is struggling just as hard as it can to keep the puppet states to its West and the Lebensraum to its East in line, significant amounts of the British Empire/Commonwealth are controlled by a sort of Free British exile government, America is the dominant superpower, etc., etc., etc.
MY question is, how can we realistically achieve the former scenario, and how would it play out from there. Little details can vary (i.e. whether Italy is a Great Power in its own right or just a Germany wannabe, whether India or the Americas are under German or Japanese influence, etc) but the end goal must be, with a POD no earlier than Hitler's election, and with WW2 starting of in an acceptably recognizable way (America CAN remain isolationist if need be) have the world be split between the Nazi German and Imperial Japanese camps by 1975.
Discuss.