With some 16 different agencies involved in the gathering of intelligence, the challenge of seeing the collective whole was dramatized by the intelligence breakdown of September 11, 2001.

An intelligence breakdown, misinformation, an honest error.

The 601-page document detailed many U.S. intelligence failures and identified intelligence breakdowns in dozens of cases.

It is followed by chapters on intelligence breakdowns, missteps in Afghanistan and Iraq, and problems in Pakistan, Saudi Arabia, Syria, Iran, Israel and Turkey.

Yet it was the second group, a joint panel of the House and Senate intelligence committees, that for now has the primary responsibility for pursuing intelligence breakdowns in the days before Sept. 11.

He described the intelligence breakdown as a systems failure and said only an independent investigation would be able to set things right.

Mr. Montesinos took heavy criticism from rivals within the security apparatus for the intelligence breakdown that led to the guerrilla hostage-taking last December.

The work we had done together in the past was Bureau stuff: intelligence breakdown, communications, liaison, so forth.

In the immediate aftermath of Sept. 11, members of Congress were reluctant to order an inquiry into the intelligence breakdown on the grounds that it might undercut the American military campaign or deflect law enforcement agencies from their duties.

The failure to identify the reorganization of the defenses was a rare intelligence breakdown for the allies.