Historians often designate certain years as turning points. 1492: Columbus sails forth with the blessing of Queen Isabella and King Ferdinand, while the Spanish Inquisition expells Jews from Spain. 1517: Martin Luther nails the 95 theses to the doors of Castle Church in Wittenberg, Germany. 1848: liberal revolutions topple governments throughout Europe, as Karl Marx publishes The Communist Manifesto.  1938: Prime Minister Chamberlain's appeasement of Hitler fatefully rearranges the map of Europe. In his new book, "Strange Rebels: 1979 and the Birth of the 21st Century,"  journalist Christian Caryl argues that the year 1979 radically changed the course of history. As Deng Xiaoping moved Communist China to a market-based economy, the Ayatollah Khomeini emerged from exile and returned triumphantly to Iran. A young woman named Margaret Thatcher took the reins of power in Britain, while Pope John Paul II inspired millions of Polish citizens living under Communist rule. Caryl argues that 1979 marked the beginning of the end for Communism, the rise of the market-based economy, and political radicalization of religion: hallmarks of the modern era.