A report on the performance of a little-known intelligence agency during the Vietnam War has finally been published after being kept secret for 35 years. The agency is the State Department’s Bureau of Intelligence and Research, known to insiders as INR. Historians are finding the report a valuable resource that rivals the Pentagon Papers, a secret Defense Department history of the Vietnam War that newspapers published in 1971 over strenuous government objections.

The study’s several hundred pages show how the small agency, with a total staff of only 350, often outshone the huge Central Intelligence Agency and the Defense Intelligence Agency in appraising the weaknesses of the South Vietnamese government and the strength and determination of the communist Viet Cong guerrillas and their supporters in North Vietnam.

Publication was achieved through a Freedom of Information request by the National Security Archive, a non-governmental nonprofit research organization in Washington, D.C. The archive is looking for a publisher to put the study into book form. It has been posted online at www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB121/.

INR Director Thomas L. Hughes ordered the study in 1968, and a team of researchers completed it in 1969. Mr. Hughes, now retired, could not read it until last year, when he wrote a “retrospective preface” that is included in the posting. He contrasted INR’s consistent and outspoken skepticism and pessimism about the Vietnam War with the public silence of many officials of the Johnson and Nixon administrations, including many who opposed the war. He called them “hawks by day and doves by night.” He said those who worked at INR in the 1960s had the “ironic satisfaction of knowing that most of our forecasts have been validated by history. We can only lament that, while we were heeded, we were unable to persuade, sway, or prevail when it came to the ultimate decisions.”

John Prados, a senior fellow at the archive, in a lengthy commentary on the study, concluded that the Vietnam-era history shows the value of having a number of competing intelligence agencies rather than the unified intelligence system that some are urging. He noted that INR’s independent appraisals often contradicted those of the larger agencies and helped curb further escalation of the war and may have averted Chinese intervention and a far wider war.

In the current Iraq war, INR a year ago criticized the theory that a democratic Iraq could become a peaceful model for the rest of the Middle East. ”

It also warned in advance that Turkey feared the prospect of Kurdish autonomy and might not let U.S. troops cross its border and enter Iraq from the north.

Such independence may have had its costs. Mr. Prados says that INR was excluded this year from the annual World Threat Briefing before Senate and House committees. The CIA, the DIA and the National Security Agency all took part, but, for the first time, not the INR.

Congress and the White House would do well to pay attention to INR. Its intelligence track record could encourage elected leaders to speak up when the INR’s work contradicts the popular theory of the moment.