CIA spokesman George Little defended the policy, saying the agency has a "wide range of effective capabilities at our disposal to pursue terrorists and thwart their activities. Our efforts in recent years have led to a number of counter-terrorism successes that have saved lives."
The current rules may be flexible in any case. At a hearing in February, Chambliss asked CIA Director Leon E. Panetta what would happen if the U.S. caught Osama bin Laden or his top aide, Ayman Zawahiri. Both men are believed to be hiding in Pakistan.
"We would probably move them quickly into military jurisdiction" for questioning at Bagram air base in Afghanistan, "and then eventually move them probably to Guantanamo," Panetta replied.
James R. Clapper, director of national intelligence, quickly added that the question had not been resolved, however.
That indecision has led to frustration in one recent case.
In February 2010, the CIA helped Pakistani intelligence officers arrest Mullah Abdul Ghani Baradar, the Taliban's military leader, in Karachi. U.S. officials describe him as the most senior Taliban figure captured since the Afghanistan war began in 2001.
Baradar remains in Pakistani custody, and CIA officers are not satisfied with their access to him, according to two U.S. officials who have been briefed on the matter.
"We just don't have something in place that works" outside Iraq and Afghanistan, said Louis Tucker, former staff director of the Senate Intelligence Committee. "We're kind of just flying by the seat of our pants."
Times staff writer Alex Rodriguez in Islamabad, Pakistan, contributed to this report.