1948: West Berlin, Germany, is blockaded by the Soviets. The Americans begin an airlift to help the stranded Berliners.

1984: The Berlin wall, built in 1961 to keep East Germans from defecting to the West, remains in place.

Today: East and West Germany are reunified, after the Berlin wall was taken down in 1990.

1948/49: Mao Tse-tung battles Chiang Kai-shek and his nationalist forces, finally defeating them in 1949 and establishing a totalitarian communist regime.

1984: China has survived the severe cultural purging of the Great Proletarian Cultural Revolution in the 1960s. Opened to the West in the 1970s because of President Nixon's visit in 1972, China is now trading with the West and incorporating some small democratic and economic reforms.

Today: In 1989, students demanding greater economic and civil rights reforms protested in Tiananmen Square in Beijing and were gunned down by Chinese troops. China continues to trade with the West, but...