Just days after the 9-11 attacks, a senior Pentagon analyst eased her red Toyota Echo into traffic and headed to work. She never saw the undercover cars tracking her every turn. As she settled into her cubicle on the 6th floor of the Defense Intelligence Agency in Washington, FBI Agents and twitchy DIA officers were hiding in nearby offices. For this was the day that Ana Montes--the US Intelligence Community superstar who had just won a prestigious fellowship at the CIA--was to be arrested and publicly exposed as a secret agent for Cuba.   Like spies Aldrich Ames and Robert Hanssen before her, Ana Montes blindsided her colleagues with brazen acts of treason. For nearly 17 years, Montes succeeded in two high-stress jobs. By day, she was one of the government’s top Cuba experts, a buttoned-down GS-14 with shockingly easy access to classified documents. By night, she was on the clock for Fidel Castro, listening to coded messages over shortwave radio, passing US secret