The most significant changes recommended by the 9/11 Commission require some agencies, most notably the Department of Defense, to relinquish some of their power. But, as commission member Bob Kerrey (who is not related to the presumed Democratic presidential candidate) points out, that is a notoriously difficult thing to do.

"In my experience in politics, when somebody is asked to give up something, they will come up with all kinds of reasons other than the most important one, which is that they don't want to surrender authority, to cite for why they don't want to do it," he said.

The commission proposes creating the post of Director of National Intelligence, a sort of intelligence super-chief. Currently, the head of the CIA is also the director of Central Intelligence, the president's top intelligence advisor and the nominal head of a loose grouping of agencies that deal in domestic and foreign intelligence.

The idea is not a new one and has been proposed numerous times over the past 30 years. But, as Kevin O'Connell, director of the Intelligence Policy Center at the RAND Corporation, says, it remains a controversial one.

"Some believe, on the one hand, that it creates a central point for accountability in American intelligence," said Mr. O'Connell. "But on the other hand, some are concerned that it would create another layer of bureaucracy in an already complicated intelligence structure."

Contrary to popular perception, the Department of Defense actually controls more intelligence funds and people than the CIA. Richard Best, a defense and intelligence analyst for the Congressional Research Service, says any efforts to strip any of that authority away will, to use a military term, encounter stiff resistance, both from the Pentagon and its political allies in Congress.

"To take them out of the military chain of command, to take them out from under the secretary of defense would be a very difficult process," he added. "There are many folks within the military who would be very reluctant to see this happen because they fear that they would be devoted to other types of analysis, other types of collection, and reduce the amount that's available to what they call the warfighters, the military commanders."

Mr. O'Connell says that, for such a proposal to work, the new job must have real power and authority over people and budgets.

"If it's a change that's going to be made effectively, it's going to have to be done by creating something more than a ceremonial position," said Mr. O'Connell. "Certainly, it will have to have Cabinet-level rank. But it will also have to have other important responsibilities, such as budget reprogramming authority and certainly the ability to approve agency heads of the various entities within the American intelligence community."

The commission backed away from the suggestion, however, that the post be of Cabinet-level rank.