Heinz Guderian stated that the fight was mainly between the Soviet Union and the United States: "People resent the fact that while the United States followed a policy of German disarmament and of friendship with Russia after the war, it now advocates rearmament they could just as easily argue that it was for cooperation with the Soviet Union and to change its policy."[3] On August 29, 1949, the Soviet Union exploded RDS-1, an atomic bomb, at Semipalatinsk in Kazakhstan. This forced a reevaluation of the defense requirements of Western Europe.