The extraordinary life of Jay Lovestone is one of the great untold stories of the twentieth century. A Lithuanian immigrant who came to the United States in 1897, Lovestone rose to leadership in the Communist Party of America, only to fall out with Moscow and join the anti-Communist establishment after the Second World War. He became one of the leading strategists of the Cold War, and was once described as "one of the five most important men in the hidden power structure of America."          Lovestone was obsessively secretive, and it is only with the opening of his papers at the Hoover Institution, the freeing of access to Comintern files in Moscow, and the release of his 5,700-page FBI file that biographer and Pulitzer Prize-winning journalist Ted Morgan has been able to construct a full account of the remarkable events of Jay Lovestone's life.          The life Morgan describes is full of drama and intrigue. He recounts Lovestone's career in the faction-riven world of American Communism until he was spirited out of Moscow in 1929 after Stalin publicly attacked him for doctrinal unorthodoxy. As Lovestone veered away from Moscow, he came to work for the American Federation of Labor, managing a separate union foreign policy as well as maintaining his own intelligence operations for the CIA, many under the command of the legendary counterintelligence chief James Angleton. Lovestone also associated with Louise Page Morris, a spy known as "the American Mata Hari," who helped him undermine Communist advances in the developing world and whose own significant espionage career is detailed here. Lovestone's influence, always exercised from behind the scenes, survived to the end of the Cold War and the demise of the Soviet Union.          A Covert Lifehas all the elements of a classic spy thriller: surveillance operations and stings, love affairs and bungled acts of sabotage, many thoroughly illegal. It is written with the easy hand of a fine biographer (The Washington Post Book World called Ted Morgan "a master storyteller") and provides a history of the Cold War and a glimpse into the machinery of the CIA while also revealing many hitherto hidden details of the superpower confrontation that dominated postwar global politics.