The Hungarian Revolution was one of the darkest events of the Cold War. The struggle began on October 23, 1956, when hundreds of thousands of Hungarians led a revolt against the Soviet-controlled government. The uprising resulted in control over numerous social institutions and much of the country. After the rebels had taken control of the government, they appointed Imre Nagy as prime minister. Nagy withdrew Hungary from the Warsaw Pact and declared neutrality. On November 4, 1956, the Soviet Army burst into Hungary to re-establish control, and in January 1957, Janos Kadar, Nagy's colleague, was installed as prime minister. President Dwight D. Eisenhower and many others in Washington, D.C., had watched in frustration, fearing the outbreak of a global war if they intervened. The revolts in Hungary (and Poland) compelled a change in Soviet thinking by general secretary Nikita Khrushchev and others in the Kremlin. What developed was an agreement to allow Eastern European nations a measure of self-governance.