In 1958–59, Khrushchev acted aggressively, most notably with his ill-conceived attempt to force the Allies out of Berlin. This move was partly a response to Mao's actions in the Taiwan Strait and a similar calculation of war risks. Both leaders believed their gambles would not trigger a military response from the United States, but Khrushchev soon realized he had miscalculated. Instead of adhering to his deadline, Khrushchev engaged the West in a dialogue. In September 1959, he visited the United States, gaining the recognition he so desired. Meanwhile, the Great Leap Forward, which Mao launched to prove that China was better than the USSR at building socialism, resulted in a massive famine in China. The failure of the Great Leap boosted Khrushchev's confidence, but Sino-Soviet relations continued to worsen.