Senator Hubert Humphrey. The hearings featured conflicting testimony from the likes of Teller and Linus Pauling, as well as from Harold Stassen, who argued that a test ban could safely be separated from broader disarmament, and AEC members, who argued that a cutoff in nuclear production should precede a test ban. Khrushchev and a moratorium: 1958–1961 In the summer of 1957, Khrushchev was at acute risk of losing power, as the Anti-Party Group composed of former Stalin allies Lazar Kaganovich, Georgy Malenkov, and Vyacheslav Molotov launched an attempt to replace Khrushchev as General Secretary of the Communist Party (effectively the leader of the Soviet Union) with Nikolai Bulganin, then the Premier of the Soviet Union. The attempted ouster, which was foiled in June, was followed by a series of actions by Khrushchev to consolidate power. In October 1957, still feeling vulnerable from Anti-Party Group's ploy, Khrushchev forced out defense minister Georgy Zhukov, cited as "the nation's most powerful military man." On 27 March 1958, Khrushchev forced Bulganin to resign and succeeded him as Premier. Between 1957 and 1960, Khrushchev had his firmest grip on power, with little real opposition. Khrushchev was personally troubled by the power of nuclear weapons and would later recount that he believed the weapons could never be used. In the mid-1950s, Khrushchev took a keen interest in defense policy and sought to inaugurate an era of détente with the West. Initial efforts to reach accords, such as on disarmament at the 1955 Geneva Summit, proved fruitless, and Khrushchev saw test-ban negotiations as an opportunity to present the Soviet Union as "both powerful and responsible." At the 20th Communist Party Congress in 1956, Khrushchev declared that nuclear war should no longer be seen as "fatalistically inevitable." Simultaneously, however, Khrushchev expanded and advanced the Soviet nuclear arsenal at a cost to conventional Soviet forces (e.g., in early 1960, Khrushchev announced demobilization of 1.2 million troops). On 31 March 1958, the Supreme Soviet of the Soviet Union approved a decision to halt nuclear testing, conditional on other nuclear powers doing the same. Khrushchev then called on Eisenhower and Macmillan to join the moratorium. Despite the action being met with widespread praise and an argument from Dulles that the US should reciprocate, Eisenhower dismissed the plan as a "gimmick"; the Soviet Union had just completed a testing series and the US was about to begin Operation Hardtack I, a series