The Nazis might be called something else, but there will still be a big revanchist party aching to settle scores from WWI. The German military will back that party, and then WWII begins.
A Second World War was by no means guaranted, there were plenty of PODs were it could have been avoided.
A question:
Could a non-communist Russia butterfly away the Economic Crisis of the late 20s?
If I remeber correctly it started out as a minor overproduction crisis in the States. So if Russia is capitalist and imports a lot of industrial products from America (they even tryed to import half their ammo during the First World War) that could prevent the crisis.