The Berlin Blockade in 48-49? How you'd get that to turn nasty I don't know, maybe the air bridge fails and the Allies try to run the blockade rather than withdraw?
By the time of the blockade it gets REALLY ugly if the West and USSR go to war.
The Western armies have more or less evaporated back into civilian life except for cadre while the Red Army is, while not the Fall 1945 force, still quite large in number. (frex: At the time the Blockade started the USAF had exactly two squadrons of fighters in Germany, one P-47 and one P-80). What the U.S. has, in the low triple digits, are nuclear weapons and the aircraft to deliver them (although the loss rate over the USSR would make the Daylight campaign in 1943 look like a Scout Jamboree).