Gulf of Tonkin Incident - NSA Report

NSA Report

In October, 2005 the New York Times reported that Robert J. Hanyok, a historian for the U.S. National Security Agency, had concluded that the NSA deliberately distorted the intelligence reports that it had passed on to policy-makers regarding the August 4, 1964 incident. He concluded that the motive was not political but was probably to cover up honest intelligence errors.

Hanyok's conclusions were initially published within the NSA in the Winter 2000/Spring 2001 Edition of Cryptologic Quarterly, about five years before they were revealed in the Times article. According to intelligence officials, the view of government historians that the report should become public was rebuffed by policymakers concerned that comparisons might be made to intelligence used to justify the Iraq War (Operation Iraqi Freedom) that commenced in 2003. Reviewing the NSA's archives, Mr. Hanyok concluded that the NSA had initially misinterpreted North Vietnamese intercepts, believing there was an attack on August 4. Midlevel NSA officials almost immediately discovered the error, he concluded, but covered it up by altering documents, so as to make it appear the second attack had happened.

On November 30, 2005, the NSA released the first installment of previously classified information regarding the Gulf of Tonkin incident, including a moderately sanitized version of Mr. Hanyok's article. The Hanyok article stated that intelligence information was presented to the Johnson administration "in such a manner as to preclude responsible decision makers in the Johnson administration from having the complete and objective narrative of events." Instead, "only information that supported the claim that the communists had attacked the two destroyers was given to Johnson administration officials."

With regard to why this happened, Hanyok wrote:

As much as anything else, it was an awareness that President Johnson would brook no uncertainty that could undermine his position. Faced with this attitude, Ray Cline was quoted as saying "... we knew it was bum dope that we were getting from Seventh Fleet, but we were told only to give facts with no elaboration on the nature of the evidence. Everyone knew how volatile LBJ was. He did not like to deal with uncertainties."

Hanyok included his study of Tonkin Gulf as one chapter of an overall history of the involvement of NSA, and American signals intelligence (SIGINT), in the Indochina Wars. A moderately sanitized version of the overall history was released in January 2008 by the National Security Agency and published by the Federation of American Scientists.