After President Kennedy's assassination, direct tensions between the superpower countries of US and Soviet Union developed into a contest with proxy wars, insurgency funding, puppet governments and other overall influence mainly in Latin America, Africa, and Asia. This "Cold War" dominated the world's geopolitics during the decade. Africa was in a period of radical political change as 32 countries gained independence from their European colonial rulers. The heavy-handed American role in the Vietnam War lead to an anti-Vietnam War movement with outraged student protestors around the globe. By the end of the 1950s, post-war reconstructed Europe and began an economic boom. World War II had closed up social classes with remnants of the old feudal gentry disappearing. A developing upper-working-class (a newly redefined middle-class) in Western Europe could afford a radio, television, refrigerator and motor vehicles. The Soviet Union and other Warsaw Pact countries were improving quickly after rebuilding from WWII. Real GDP growth averaged 6% a year during the second half of the decade; overall, the worldwide economy prospered in the 1960s with expansion of the middle class and the increase of new domestic technology. During the 1960s, the world population increased from 3.0 to 3.7 billion people. There were approximately 1.15 billion births and 500 million deaths. Politics and wars Wars The Cold War (1947–1991) The Vietnam War (1955–1975) 1961 – Substantial (approximately 700) American advisory forces first arrive in Vietnam. 1962 – By mid-1962, the number of U.S. military advisers in South Vietnam had risen from 900 to 12,000. 1963 – By the time of U.S. President John F. Kennedy's death there were 16,000 American military personnel in South Vietnam, up from Eisenhower's 900 advisors to cope with rising guerrilla activity in Vietnam. 1964 – In direct response to the minor naval engagement known as the Gulf of Tonkin incident which occurred on 2 August 1964, the Gulf of Tonkin Resolution, a joint resolution of the U.S. Congress, was passed on 10 August 1964. The resolution gave U.S. President Lyndon B. Johnson authorization, without a formal declaration of war by Congress, for the use of military force in Southeast Asia. The Johnson administration subsequently cited the resolution as legal authority for its rapid escalation of U.S. military involvement in the Vietnam War. 1966 – After 1966, with the draft in place more than 500,000 troops are sent to Vietnam by the Johnson administration and college attendance soars.