Title: Military occupations by the Soviet Union
Content: Soviet Union, reacted to these reforms by announcing the "Brezhnev Doctrine", and on 21 August 1968, about 750,000 Warsaw Pact troops, mostly from the Soviet Union, Poland, Bulgaria and Hungary, with tanks and machine guns occupied Czechoslovakia, deported thousands of people and rapidly derailed all reforms. Most large cities were individually invaded and overtaken; however, the invasion's primary attention focused on Prague, particularly the state organs, Czech television and radio. The Czechoslovak government held an emergency session, and loudly expressed its disagreement with the occupation. Many citizens joined in protests, and by September 1968 at least 72 people had died

Title: Cold War
Content: began the development of an independent French nuclear deterrent. In 1966 he withdrew France from NATO's military structures and expelled NATO troops from French soil. In 1968, a period of political liberalization took place in Czechoslovakia called the Prague Spring. An "Action Program" of reforms included increasing freedom of the press, freedom of speech and freedom of movement, along with an economic emphasis on consumer goods, the possibility of a multiparty government, limitations on the power of the secret police, and potential withdrawal from the Warsaw Pact. In answer to the Prague Spring, on 20 August 1968, the Soviet Army,

Title: Brezhnev Doctrine
Content: retroactively justify the invasion of Czechoslovakia in August 1968 that ended the Prague Spring, along with earlier Soviet military interventions, such as the invasion of Hungary in 1956. These interventions were meant to put an end to liberalization efforts and uprisings that had the potential to compromise Soviet hegemony inside the Eastern Bloc, which was considered by the Soviet Union to be an essential defensive and strategic buffer in case hostilities with NATO were to break out. In practice, the policy meant that only limited independence of the satellite states' communist parties was allowed and that no socialist country would

Title: Cold War (1962–1979)
Content: towards capitalism. The invasion was followed by a wave of emigration, including an estimated 70,000 Czechs initially fleeing, with the total eventually reaching 300,000. In April 1969, Dubček was replaced as first secretary by Gustáv Husák, and a period of "normalization" began. Husák reversed Dubček's reforms, purged the party of liberal members, dismissed opponents from public office, reinstated the power of the police authorities, sought to re-centralize the economy and re-instated the disallowance of political commentary in mainstream media and by persons not considered to have "full political trust". The international image of the Soviet Union suffered considerably, especially among

Title: Eastern Bloc
Content: and the exercise of a Soviet right to intervene if an Eastern Bloc country appeared to shift towards capitalism. The invasion was followed by a wave of emigration, including an estimated 70,000 Czechoslovaks initially fleeing, with the total eventually reaching 300,000. In April 1969, Dubček was replaced as first secretary by Gustáv Husák, and a period of "normalization" began. Husák reversed Dubček's reforms, purged the party of liberal members, dismissed opponents from public office, reinstated the power of the police authorities, sought to re-centralize the economy and re-instated the disallowance of political commentary in mainstream media and by persons not

Question: Which country's liberalization program was halted by the invasion of 600,000 Soviet troops in 1968?
Answer: Czechoslovakia