You would have to believe there never was
Daniel Ellesberg
and
The Pentagon Papers
"What I particularly learned, though, in 1969, and from the Pentagon Papers, was that Nixon, the fifth president in a row now, was choosing to prolong the war in vain hopes that he might get a better outcome than he could achieve if he'd just negotiated his way out and took what he could get and accepted, essentially, a defeat. He hoped to do much better than that. In fact, he hoped to hold on to control of Saigon and the major populated areas indefinitely for the United States, that these would be subject to our will and our policy and not be run by communists. And he hoped to do that, actually, in ways similar to the way Johnson had hoped -- by threatening escalation of the war, threatening bombing of North Vietnam. He was making such threats and then he was prepared to carry them out.
I did not believe the threats would succeed, so I foresaw a larger war. He was fooling the public about what he was doing at this time for the same reason Johnson had in 1964. The public would not, at that time, have supported a continuation of the war, let alone an expansion of the war. But he was successfully fooling the public, who didn't want to believe that any president could be so foolish and so narrow minded in his own interests as to keep that war going after the Tet offensive of 1968. So I saw a replay of 1964 and 1965 coming again. I saw once again a president making secret threats, almost sure to carry them out, and deceiving the public as to what he was doing.
By reading the Pentagon Papers, which I finished doing in the fall of 1969, in September 1969, I now had a historical sweep sufficient to reach a conclusion that I would have been very unlikely to reach without reading them, and that was that there was very little hope of changing his
mind from inside the executive branch, for example, by giving him good advice or by giving him realistic estimates of what was happening in Vietnam. Because what I saw by reading the earliest days of the Pentagon Papers, going back to 1945 and 1946, was that every president had had such advice, as early as Truman. Truman had seen predictions of an indefinitely prolonged guerrilla war facing him and yet had gone ahead in supporting the French in this effort. And this had happened year after year. It happened year after year for Eisenhower and Kennedy and Johnson. The fact now that Nixon was embarked on a new course held out very little hope that he would be more responsive just to good advice about getting out than any of his predecessors had been."
http://globetrotter.berkeley.edu/people/Ellsberg/ellsberg98-6.html