Answer:
The Soviet failure to send agricultural goods to the West and their continued extradition of Germans from the East led the West to fear a Communist bloc being created. The Western powers did not want this to happen and feared that it could spread. The result was the creation of Bizonia and US pressure on Western voters to vote for democratic parties: in Italy, US officials said that US aid would be withdrawn if the Communists won and in West Germany the Communist party was banned altogether.
In doing so the US were trying to maintain the security of the Democratic nations in the West.