To answer this question clearly, it is first necessary to study Germany's place in the "cold war".
Already, in 1945, differences between the Allies had risen to about the future of Poland, of Western Europe in general, of France's role in the post-war world. But on the German question, the Big Three made considerable efforts to avoid any conflict. And when Winston Churchill, in 1946, in his famous speech delivered in Fulton, Missouri, declared that an iron curtain "was descending over Europe", he was careful to situate the dividing line outside of Germany proper. . The Iron Curtain,” he says, ran from Stettin, on the Baltic, to Trieste, on the Adriatic—that is, behind the eastern border of the Russian occupation zone. It was clear that Churchill at that time was still thinking in terms of cooperation between the four great powers in Germany.
He worried about a possible division of Europe but not about a possible conflict between the Big Four in Germany. It must be recognized, moreover, that if there were serious disagreements between the great powers, they had not yet degenerated into a struggle for control of Germany.
This struggle began soon after. And it started in Berlin. In 1946, the Soviet administration, in the eastern zone, had carried out a more or less forced merger of the Communist and Socialist parties and sought to extend this measure to the city of Berlin. Western military commanders were extremely slow to see the implications, although the Germans were immediately aware of the danger it posed. Unification of the Communist and Socialist parties would have given the political allies of the Soviet Union an overwhelming electoral majority in Berlin.
Berlin was still considered the capital of a provisionally divided Germany because, by the Potsdam agreements, the Big Three had pledged to quickly establish a centralized administration for all of Germany. With a strong pro-Soviet majority in the city, which could well lose its function as Germany's capital, Stalin would be well on his way to seizing political control of the entire country.
It is highly likely that the Soviets during this period were organizing their area not to become a separate communist state, but to serve as a springboard for the expansion of communism into the rest of the country. Berlin was to be the next step.
The leaders of the Socialist Party in Berlin feared the merger with the Communists and demanded a referendum in the party. The referendum was held with the agreement of the Western powers (in the Western sectors only) and the voters, with an overwhelming majority, decided against the merger of the two parties.
It was then the turn of the Russian commander to call for elections in all sectors of Berlin in order to give all voters - and not only members of the "socialist parties" - the opportunity to decide whether they wanted to be represented by the reactionary social democrats or the progressive unified socialist party. The Soviet move turned out to be a catastrophic mistake. Elections were held in the fall of 1946 and, to the surprise of the Soviets alone, the Communists suffered a severe defeat in all three western sectors. Naturally, as expected, they won a decisive victory in the Soviet sector.