MAJOR STUDENT AND URBAN UNREST surfaced in many countries. In the United States, there were student demonstrations in many cities in opposition to U.S. involvement in Vietnam, and in the summer there were urban riots in Cleveland (July) and violent street demonstrations during the Democratic National Convention in Chicago (July). There were civil riots in Northern Ireland (Oct.) and a near revolution in FRANCE following violent student outbreaks and strikes by workers in a number of industries (May–June). Similar disturbances took place in West Germany (April), Poland, Mexico (Sept.), Brazil (March–April), Pakistan (Oct.), and Japan. The “Prague Spring,” involving political liberalization in Czechoslovakia, was crushed by a Soviet invasion (Aug.).
Pope PaulVI issued the encyclical Humanae vitae, which upheld the Church's traditional opposition to artificial methods of birth control, despite recognition by the papal advisory commission of the problems of global overpopulation.
