At 6:30 p.m. on Sept. 14, Ana Belen Montes, a senior analyst at the Defense Intelligence Agency (DIA), walked into a public telephone booth outside Washington's National Zoo and made two calls to pager numbers later traced by federal agents to Cuba's Directorate of General Intelligence (DGI). She already had compromised the identities of CIA agents, revealed U.S. military secrets and exposed the contents of classified files. But, as Montes sent repeated signals to her DGI handlers during the days immediately following the Sept. 11 terrorist attacks on the Pentagon and the twin towers of the World Trade Center, the ...