Well in my opinion Stalin was not planning to attack Germany. If he was then the largest concentration of Red army forces would of been the Baltic and Western Special military districts (i.e. the ones with the most border with Germany). The strongest military district was the Kiev military district. This could be interpreted two ways, as a defensive measure, after all capitalist imperialist wage war for resources and markets and the Ukraine certainally had resources. Or it was an offernsive measure aimed at Balkins not Germany.
On a side note here the USSR was continuing to argue with Romanian about exactly where it's new frontier stood. The most important point being the islands at the mouth of the Danube. Russain wanted to control all of these and thus access from the Danube into the Black Sea, Romania was reported to be less than impressed at this idea. The USSR was also putting presure on Balgarian to sign an alliance with the USSR, allowing the Soviet basing rights there, and the Soviets always had an eye on the straights, a push through the Balkins was one way of getting there.
On a side note here the USSR was continuing to argue with Romanian about exactly where it's new frontier stood. The most important point being the islands at the mouth of the Danube. Russain wanted to control all of these and thus access from the Danube into the Black Sea, Romania was reported to be less than impressed at this idea. The USSR was also putting presure on Balgarian to sign an alliance with the USSR, allowing the Soviet basing rights there, and the Soviets always had an eye on the straights, a push through the Balkins was one way of getting there.