Thing about Stalin was that, evil and brutal as he was, he tended to follow treaties (unlike his fellow mass murder Hitler, who never signed anything he intended to follow). He would have been more than happy to wait until the Molotov Treaty ran out before he acted. That would have allowed him time to fully reequip and retrain his army, build up reserves, and crush Hitler at his leisure.
Stalin NEVER wanted a war with Germany. He didn't like or trust Hitler, but then he didn't trust the democracies either. As a revolutionary he saw how war agaist Germany ruined the Czar and was very aware that it could happen again. When he was still negotiating with the British and French he always made one point very clear; that the Soviet Union was NOT going to fight Germany alone. It was hie belief that the Allies were trying to manuever them into that position that led to the M-R pact.
Even if two or three years had passed and the Red Army had been reformed and re-equipped Stalin would have continued to see war with Germany as a possible road to ruin. His efforts at appeasement just before Barbarossa show just how far he was willing to go to avoid war.
Stalin would NEVER have chosen war so long as Germany was still strong.
The only way he would have were if British and Americans armies were in the Ruhr and headed to Berlin. As with Japan he would have jumped in against an already beaten enemy to grab some cheap spoils.
He would not have chosen to enter a life and death struggle.
Ok so from what I've gathered Stalin would be very reluctant to attack Germany regardless of anything so the idea should be modified, either we push through to make him attack by creating a big provocation or act of war. (Assassination of Stalin himself probably?) Or we use Stalin passiveness to give Germany more time to prepare for a war against him and allocate more resources to African campaign? What do you think.