The deployment came in response to the urgent request of Lebanese president Camille Chamoun after sectarian violence had erupted in the country. Washington considered the military intervention successful since it brought about regional stability, weakened Soviet influence, and intimidated the Egyptian and Syrian governments, whose anti-West political position had hardened after the Suez Crisis.[242]
Most Arab countries were skeptical about the "Eisenhower doctrine" because they considered "Zionist imperialism" the real danger. However, they did take the opportunity to obtain free money and weapons. Egypt and Syria, supported by the Soviet Union, openly opposed the initiative. However, Egypt received American aid until the Six-Day War in 1967.[243]
As the Cold War deepened, Dulles sought to isolate the Soviet Union by building regional alliances of nations against it. Critics sometimes called it "pacto-mania".[244]

1960 U-2 incident
Main article: 1960 U-2 incident
A U-2 reconnaissance aircraft in flight
On May 1, 1960, a U.S. one-man U-2 spy plane was shot down at high altitude over Soviet airspace. The flight was made to gain photo intelligence before the scheduled opening of an east–west summit conference, which had been scheduled in Paris, 15 days later.