I think that war occurs anyway. Stalin wanted to get into the Baltics and probably take a bite out of Poland.
However, without Hitler pushing things to a boiling point is Stalin going to have the guts to go after the Baltics?
I think that he probably would. If Hitler doesn't to power, then I think that you're still going to have political instability in Germany. When Stalin decides that no-one will be able to keep him from expanding in the East, he swings into action and builds up troops along the Baltics' border. Then forces annexation of the Baltics. This is going to upset people in the West, and probably creates a crisis in the East. Poland will freak out. Really, really, freak out. Germany might press its luck now and try to get some of the Polish Corridor back, using the implicit threat of an alliance with the Soviets out as motivating factor for the Poles. Or it might try and expand "soft" influence by arranging a defensive alliance with Poland and Czechoslovakia.
Using the Soviet expansion as an excuse the Germans could unveil their violations of the Versailles Treaty and expand its arms programs. Rather than be seen as a threat to its neighbors Germany is the only power that has both the will and capacity to defend Europe against the Soviets.
The Soviet expansion is going to end up stabilizing politics in Germany. The new German posture as the lynch-pin of the Warsaw Pact (Germany, Poland, Romania), ends up propelling a center-right coalition to a stable hold on the German government.
The Soviets don't expand much beyond the Baltics. A failed invasion of Finland (1940-2) ends up as a proxy war between the newly reinvigorated German arms industry and the Soviet Union. German "volunteers"- mostly air units are sent in '41- and are seen as convincing the Soviets to end their attack.
WWII doesn't happen. The Japanese still launch their invasion of China. The Americans, without the war in Europe, are unable to cut off oil, so the Japanese never face the end of their imperial ambitions via lack of resources. Instead Japanese imperial ambitions go to China to die. The Japanese are more successful, but are unable to ever really win. Because of more Japanese focus on China, the Nationalists take even more of a beating. The Soviets became more involved in the Sino-Japanese War, building the Chinese Communist Party up in the process. The Soviets get a feel of how to build up a revolutionary movement, and now have a blueprint for how to do it. The Japanese face growing resistance are ultimately forced to withdraw from China in '51.
Soviets start backing nascent nationalist movements across the West's imperial holdings. The British and French have more manpower, and have not been exhausted by WWII, so they can stand up to growing independence movements more easily. This leads to a much bloodier situation as the Algerian war progresses. Everything that OTL was seen as a communist conspiracy really ends up becoming one. The Soviets, without the massive losses and stresses from WWII, are much more willing to engage in a match of wills with the British and French.
The Americans have a tougher time getting out of the Depression. Without WWII and the GI Bill the economic transformation that created modern America never happens. What the alternative America is isn't really clear, but it doesn't look like OTL for sure.
Weimar Germany in the 1960's is the economic powerhouse of Europe. The British and French have been plagued by political instability stemming from their increasing difficult commitments in their imperial holdings. Germany dominates central Europe with its economic strength and military might. German troops, as part of the Warsaw Pact, are still stationed in Romania and Poland. Plans for a European free trade zone between the Warsaw Pact and other central European countries. Germany's economic growth has attracted workers from across Europe, mainly Yugosalvs and other southern Europeans.