Exactly what it says on the tin, when is the earliest date after 1945 that the USSR and the United States could have conceivably entered into a shooting war without straining the bounds of plausibility?
I was reading an Alt-history thread on armchairgeneral.com that argued that the Soviets only had 2 good chances; in 45/46 because the west demob so much and the US cost atomic bomb production, and then again in the early 1950s.
The "big thinkers" on this site seem to be split on the subject. I believe CalBear once said that the American & British couldn't stop the Soviets in a ground invasion of Germany with out the use of nukes.
I know Hariog in convinced that the Soviets could have successfull attack in 46 but he bases that on what are in my opinion flawed US military studies of Soviet strength done right after WW2.