What did the soviet’s do between june 27, 1948, and may 12, 1949

The Soviets cut all the traffic to West Berlin 

Explanation

The Berlin Blockade (24 June 1948 – 12 May 1949) was one of the first major international crises of the Cold War. During the multinational occupation of post–World War II Germany, the Soviet Union blocked the Western Allies' railway, road, and canal access to the sectors of Berlin under Western control