It's important to recall that the east-west occupation zone and sector boundaries were agreed eight months before the surrender, so there was no need for horse-trading on the ground at the conflict's end, and forces were withdrawn to their pre-arranged lines.

The relevant protocol was signed in London in September 1944 by the European Advisory Commisssion representatives of the "Big Three", a Franch zone and sector being carved out of the US and British ones (as envisaged at Yalta) in a second agreement the following July. Parallel arrangements were put in place for Austria, though it retained its own national government.

Berlin's special treatment reflected its importance as the the anticipated seat of the joint Allied Control Council and the prospective capital of what was still envisaged as an eventual united Germany under its own democratic government (though preferences as to its political character of course differed).

US planners had earlier envisaged a division into occupation zones joining at Berlin, but the Committee on Post-War Programs concluded in early August 1944 that it was "not feasible because of the location of the capital" .