The Khrushchev Era and the 'Second Cold War' By em2019 1956 Khrushchev attacked Stalin at the Twentieth Party Congress 1956 Riots in Poland Apr 11, 1956 Hungarian Rising defeated 1957 Treaty of Rome signed 1958 Khrushchev's Berlin ultimatum 1959 Castro seized power in Cuba 1960 Paris summit broke down Jan 5, 1960 US U-2 spy plane shot down over USSR 1961 Frontier between East and West Berlin closed Period: 1962 to 1962 Cuban Missile Crisis Dec 9, 1962 USA warned USSR on installation go missiles in Cuba