Corrected entry: While the film revolves around Ryan, and without him there's no story, he takes part in the operation to stop the terrorist attack, even though, as an operative of the CIA, its charter prohibits him from operating within the United States.
Bishop73
11th Oct 2015
Correction: Incorrect, the CIA can and does operate in the US. The CIA is permitted to act within the US to address the specific areas of foreign intelligence, counter-intelligence, and terrorism (which is exactly what they were working on). They don't operate in the US in regards to domestic threats, which is FBI jurisdiction, although they can give aid if needed. See E.O. 13470. (Specifically section 1.7).
Bishop73