Bizone
The Bizone was the combination of the American and the British occupation zones during the occupation of Germany after World War II, and is also refered to as Bizonia, later changed to Trizonia, as Germany's controll was split even further.
In 1946, the USSR stopped delivering agricultural products from their sector (East Germany) to the more industrial western sectors and zones. In return, the American military administrator Lucius D. Clay ordered to stop the delivery of supplies back to the Soviet zone.
As a consequence, the USSR started a public relations campaign against American policy and began to obstruct the administrative work of all four sectors.
The USA and Great Britain had no other choice but to unite their zones (called "Bizone") in order to advance the development of a new political order in Western Germany. Nevertheless, this was the first step to the separation of Eastern and Western Germany.