Oops. A week ago in this space I called for a historian who would, without political bias, examine contemporary State Department and CIA reports of the runup to the famous anti-Communist bloodbath in Indonesia in 1965-66 in order to determine what if any was the American role in it. At once the mail brought precisely such a study, an article by Texas A&M associate professor H. W. Brands in the Journal of American History (Dec., 1989), and it is full of delights and surprises.

First the delights. It's tough for historians to get to CIA materials. But Brands found that Lyndon Johnson's passion for information had sucked embassy and CIA field reports straight into the White House and that, through a more open ''post-Watergate window'' of declassification, many Indonesia documents stored at the LBJ Library had come into the public domain.

Hence, through Brands, the opportunity to examine the larger searing allegation that journalist Kathy Kadane freshened (on the basis of participants' 25-year-old recollections) and that I relayed last week -- that in 1965, officials in our Jakarta embassy put the Indonesian army up to conducting a monster massacre terminating what was then regarded as theBrands found that LBJ had basically given up trying to get the Indonesian army to topple Sukarno. live possibility of a Communist takeover. At one end of our political spectrum, this sequence has been taken as a successful and rewarding preemptive geopolitical coup and at the other end as a notorious Cold War intervention and atrocity.

The title of Brands' article is ''The Limits of Manipulation: How the United States Didn't Topple Sukarno.''

He found that for many months American officials ''did their damnedest'' to prod the army to topple then-President Sukarno, who they feared might deliver Indonesia to the Communists (PKI), but that the army wouldn't move and a frustrated Johnson administration ''basically gave up.''

When the ''two-stage coup'' that saw Sukarno out and Suharto in began early on Oct. 1, 1965, it caught the administration by surprise. Our embassy's country team wasn't sure who Suharto was, and at first, there being more than one Suharto in the army's upper echelon, fixed on the wrong one. On the morning of the coup, agency officials suggested that Sukarno was actually in league with the plotters. In short, though there is nothing to be proud of here, our men in Jakarta evidently didn't have the foggiest notion of what was going on.

The army then started killing Communists. The Johnson administration, wary of congressional criticism as well as of an Indonesian backlash, stayed at a distance even when the military began requesting aid. The United States apparently did supply walkie-talkies, historian Brands found, but to no particular effect.

Brands does not address the specific recent claim that the United States gave the army 5,000 Communists' names. My own feeling now is that it could have happened in the context of the quiet American effort he reports to stay in touch with the military, but that neither the record nor logic supports the suggestion that the military needed American lists to identify its countrymen or to make up its mind to liquidate the PKI.

CIA Director Richard Helms subsequently concluded that the army's rise ''evolved purely from a complex and long-standing domestic political situation.'' Brands agrees and goes on:

''The relative noninvolvement of the United States in the fall of Sukarno would be a nonstory except that the myth of American responsibility has proved so hardy. Its survival is largely the result of American covert activities in other places and at other times. In acknowledging the limits on their ability to control events in Indonesia, officials in the Johnson administration demonstrated a restraint and humility often absent in the management of postwar foreign policy, especially in the area of secret operations. ... The United States did not overthrow Sukarno, and it was not responsible for the hundreds of thousands of deaths involved in the liquidation of the PKI. ... ''

I take this as the hard-won conclusions of an academic whose evident distaste for covert interventions has not shaken his respect for the historical facts.

It remains to note the irony that disclosure of the CIA's hand, far from indicting the agency or the country as a whole, clears Americans of the damaging lingering suspicion of responsibility for the Indonesian coup and massacre. For me, the question of the American role in Indonesia is closed.