FOR THE first time in 17 years, members of Congress and their staff have been allowed to examine U.S. intelligence documents dealing with those classified as prisoners of war or missing in action in Southeast Asia. For the last year, at the direction of Sen. Jesse Helms (R-N.C.), ranking minority member of the Senate Foreign Relations Committee, committee staff, assisted by investigators with extensive intelligence experience in Indochina and elsewhere, have been conducting an inquiry into U.S. government handling of the POW/MIA issue.

The interim staff report, to be released today, points to extensive efforts within the Defense Department to discredit live-sighting reports of POWs, as well as the mishandling and exaggeration of forensic data in order to confirm presumptive findings of death. In at least two cases, the investigators found, caskets said to contain the remains of individuals have been buried with full military honors when, in fact, the caskets were empty.

The findings of this investigation, though still incomplete, have been a long time coming. Only last May, committee investigators were still reporting roadblocks thrown up by national security agencies and the White House. These obstacles delayed publication of our book, as they delayed the investigation and muffled the voices of those who, often speaking with detailed knowledge, challenged the Department of Defense POW/MIA Fact Book claim that "No information exists presently to indicate that there are any live American POWs being held in Southeast Asia against their will." Disinformation against dissenters has been one weapon. For example, former Defense Intelligence Agency director general Eugene Tighe assembled an expert team to examine intelligence on the missing Americans. After his task force agreed unanimously that Americans were being held in Indochina, Tighe was publicly denounced by his former colleagues and his report was classified. Similarly, broadcast of Monika's "60 Minutes" segment was delayed by complaints that it gave credence to "loonies, senile intelligence officers, a wife-beater, a distraught widow."

Delay has been an equally potent weapon. As the years pass, men in captivity die and the living evidence disappears. Meanwhile, the filed evidence is "retired," "weeded" and "sanitized" in routine intelligence procedures.

Earlier this month Sen. Charles E. Grassley (R-Iowa) complained on the Senate floor that, despite Defense Department assurances last July, he and his colleagues were still being denied full access to classified files. Grassley noted that Ann Mills Griffith, the salaried head of the government-approved National League of Families, has full security clearance and that she had written the Defense Department in August arguing that members of Congress be denied similar access.

What, asked Grassley, compelled such an unreasonable attitude toward a legitimate Senate investigation of documents that were not deep national secrets affecting security today? Griffith's security clearance, Grassley noted, "has enabled her to review the very documents she has lobbied strenuously to deny members of Congress." This, he added, had given her authority to state to League members and to Congress that the secret intelligence showed no evidence that American citizens were left behind in Indochina.

After this latest public protest, permission was granted for Senate staff investigators to examine the relevant intelligence files -- but only with Grassley present. In these past two weeks, he has somehow searched through the files for long stretches of time despite his senatorial duties. The fruits of those and earlier efforts, revealed in today's interim report, suggest a secret war against those good Americans who served in Indochina, and against those who refused to abandon them.