Pirates are an age-old menace. They are also a useful index of the advance and decline of civilization. Sea-roving brigands infested the waters of the ancient world until the Roman Empire stamped them out. With the fall of Rome and the onset of the Dark Ages the pirates returned. They thrived for centuries with the connivance of England's Queen Elizabeth I and other monarchs who were willing to tolerate a level of disorder and barbarism if it meant that hired privateers like Francis Drake would cut them in on the loot. Then in the 1800s the British Royal Navy, with help from the Americans, shut down piracy's perennial havens, including the Barbary Coast, the Horn of Africa and the Malacca Straits. For almost 100 years pirates survived only in children's literature and the movies. Now pirates are back, driving speed boats and armed with cellphones and AK-47s and rocket-propelled grenades.

These modern Blackbeards are the detritus of Third World failed states, empowered by a declining U.S. Navy presence since the Cold War and an international community that has lost interest in enforcing the laws of the civilized sea. Today, as in medieval times, travelers and businessmen and especially cargo ships are learning that after they set sail they'd better watch their backs. John C. Payne's Piracy Today . will help them chart a safe course and remind them of what happens if they don't. Mr.

Payne's comprehensive survey looks at piracy as an international phenomenon that includes places such as Nigeria and Brazil little covered by the media.