c By DOUGLAS JEHL ASHINGTON, Dec. 28 - The head of the Central Intelligence Agency's analytical branch is being forced to step down, former intelligence officials say, opening a major new chapter in a shakeup under Porter J. Goss, the agency's chief. The official, Jami Miscik, the agency's deputy director for intelligence, told her subordinates on Tuesday afternoon of her plan to step down on Feb. 4. A former intelligence official said that Ms. Miscik was told before Christmas that Mr. Goss wanted to make a change and that "the decision to depart was not hers." Ms. Miscik has headed...