One of the most insightful commentaries about the Pentagon Papers, on the occasion of their full and official public release this week, is from Leslie Gelb, who headed the Department of Defense task force that wrote the studies. In an interview on NPR, Gelb strongly disagreed with the contention of Daniel Ellsberg, who leaked portions of the papers forty years ago, that the Vietnam War would not have happened if what was in the Pentagon Papers had been publicly known all along. Yes, there were government lies, says Gelb,

But the main reason we got involved in the Vietnam War was because of what we believed, namely that we were in a mortal struggle with communism - Soviet Union and China; that the domino theory applied, that if we allow North Vietnam to conquer South Vietnam, the dominoes would fall throughout Asia and the rest of the world. Almost every one of the people in the national security field believed that, including Daniel Ellsberg.

One can add that the believers included journalists who later would win fame for their exposé-like writings about the Vietnam War, including David Halberstam and Neil Sheehan—the latter being the reporter who received the leaked papers from Ellsberg. The Pentagon Papers are a wonderful resource for understanding the American involvement in the first half of the Vietnam War. I have used them repeatedly in my own writing and research. But their contents would not have trumped the very broadly held sentiments, of the sort described by Gelb, that drove the United States into the war.

The notion that revelations of secret documents can change public policies for the better comes mainly from two sources. One is the perennial though erroneous belief that if something is secret it must be more insightful and revealing than what could come from careful study of, and reflection on, what is available to anyone, even without a security clearance. The other source is the self-interest of those who leak classified material and who attempt to portray themselves as heroes rather than as information vandals who take it on themselves to decide what should be publicly revealed and what should not. Ellsberg has long struck this pose for himself, as well as more recently trying to confer hero status on the Army private whose wholesale compromise of U.S. diplomatic traffic has had the effect of impeding the conduct of all U.S. foreign policy, no matter how worthy its objectives. (Full disclosure: I have tangled with Ellsberg in discussion of these issues on the radio, with Ellsberg's contribution to the discourse deteriorating into personal attacks on me and my integrity.)

Besides the wholesale damage, there is the retail damage that comes from leakers deciding which material to reveal and which not to reveal, thus producing an incomplete picture that conforms to the leaker's own bias. When Ellsberg committed his big leak, he did not include portions of the Pentagon Papers that addressed attempts to start peace negotiations with the North Vietnamese. Those portions were officially declassified a little later in the 1970s. When I used those portions for some research I was doing at the time on peace negotiations, I paid the copying fee and got my copy from the Department of Defense. Ellsberg says he did not leak that part because he did not want to jeopardize peace negotiations or to give the government of the day an excuse not to try to negotiate. It is unlikely that would have been a result. The events covered in that portion of the Pentagon Papers, like the events in the other portions, were already in the past. The result of the selective leaking was to nurture a biased, incomplete picture of what Lyndon Johnson's administration was doing about Vietnam. I consider the U.S. intervention in Vietnam to have been as much of a tragic blunder as most Americans have come to think of it, but the peace diplomacy was a part of the overall Vietnam story—a part we would not have learned about if it were up to Ellsberg.