The moderate Chinese approach began to change in 1957, in large part because the United State had not responded positively to the PRC’s overtures. These had not been entirely disingenuous, as the Chinese had probed American reactions over the Taiwan issue in 1954 by occupying some of the islands south of shanghai, leading to the so-called first offshore island crisis. It was diffused dramatically by Zhou Enlai’s diplomacy in Bandung, but the resultant Sino-American ambassadorial meetings in Geneva soon ended in a stalemate because of the impasse over Taiwan. Meanwhile, the American response to the Geneva Conference had been to tighten up its series of alliances, including the Manila Treaty and a security pact with Taiwan (technically, the Republic of China). In fact part of the reason for the PRC’s pressure on the offshore islands was to warn off other governments from participating in the pact. The American readiness to deal with Moscow was not matched by a similar attitude towards Beijing. In 1957 the PRC reacted angrily to the news of the American deployment of nuclear-tipped missiles on Taiwan. The change was also caused by the deterioration in Sino-Soviet relations arising out of Khrushchev’s handling of de-Stalinization, what was regarded as his mismanagement of Eastern Europe and his readiness to compromise with the United State, when Mao in particular felt that it was necessary to take a sharp approach. Despite these differences the Soviet Union agreed in late 1957 to assist the PRC in developing nuclear weapons.