In November 1956, Dulles strongly opposed the Anglo-French invasion of the Suez Canal zone in response to Egypt's nationalization of the canal. During the most crucial days, Dulles was hospitalized after surgery and did not participate in the U.S. administration's decision making. By 1958 he had become an outspoken opponent of Egyptian President Gamal Abdel Nasser and prevented Nasser's government from receiving arms from the United States. That policy allowed the Soviet Union to gain influence in Egypt.