Two instant books became wildcards that impacted our politics. The 1971 Pentagon Papers illuminated the deceptions of the Vietnam War. The current Mueller Report illuminates the magnitude of Russian electoral interference.

The aftereffects of both depend on how presidents handle them. In 1971, the Papers enraged President Nixon into establishing a “plumbers unit” to plug leaks, leading to Watergate and his departure. Is the Mueller Report spurring a similar presidential overreaction?

The Pentagon Papers came out just as I was writing my dissertation on the effects of Vietnam on U.S. foreign policy. They provided case studies of rigid groupthink and the Clausewitzian tendency of wars to escalate. They also refuted the accepted theory that we had blundered into Vietnam. No, each step was deliberate, carried out in a pessimistic atmosphere that aimed, after a while, at simply avoiding defeat. Doubts at the top appeared in late 1965.

Defense Secretary McNamara commissioned the study of decision-making in 1967. The staff of 36 produced a 7,000-page study and turned it in five days before Nixon took office. Promptly forgotten, its dozen copies might have lain eternally unknown and unused had not Daniel Ellsberg photocopied the set at Rand and, after trying to give them to Congress, passed them on to The New York Times and The Washington Post.

The Papers had little influence on the war. By mid-1971, we were already halfway out of Vietnam. Nixon aimed at extrication without humiliation by “vietnamization.” He knew it might not work but had to end a bad war. Kissinger earlier told visitors at Harvard that the best we could hope for was a “decent interval” of two to three years between U.S. withdrawal and North Vietnamese takeover. Hanoi got the message and waited until 1975 before conquering the south. By then, neither Congress nor the public much cared.

Starting with Korea, U.S. wars have begun with two-thirds popular support. Within three years, as casualties mounted and no end in sight, support declined to one-third, a point reached in early 1968 with Tet. (And the cause was not television; Korea was essentially pre-TV.) Likewise, the public tired of Afghanistan and Iraq. Trump harvested the mood, which now is leery of another Mideast war.

The differences between the Papers and the Report are many. The Pentagon Papers — written by journalists and an exciting read — were secret and emerged as a surprise. The Mueller Report — written by lawyers and reads like it — merely solidified charges of Russian interference that the intelligence agencies started communicating in 2016, although the scope of the Russian effort was not clear until after the election.

But could the two books have similar aftereffects? That is, could both lead toward impeachment? If Nixon had handled the Papers calmly, he could have finished his second term. But he treated them as a personal affront to his power. Actually, the Papers chiefly blamed JFK and LBJ and ended in 1967, before Nixon took office. Nixon could have shrugged and said, “Well, that’s the Democrats for you,” but chronic insecurity destroyed him.

Likewise, Trump is overreacting, treating the Mueller Report as a personal affront to his power. He could shrug and say, “Well, that’s the Russians for you. But I had nothing to do with it, and it did not affect the electoral outcome” (probably did). Instead, by denying there even were Russian efforts, he picks fights with Congress. He could urge publication of the whole Report and full congressional investigations. As Nixon discovered, the coverup is worse than the crime.

And Trump could protect himself by rejecting Putin’s unbelievable denials of interference in U.S. elections or in Venezuela. He could increase sanctions on Russian oligarchs and funds for cyberwarfare. By supporting Kurds, he could get Russia bogged down in Syria. And Putin would be most unlikely to retaliate by admitting to Russian cyberpenetration. Trump’s reflexive pugnacity toward his domestic critics, however, digs him into deeper holes.

The Mueller Report illustrates the breadth of Moscow’s effort. Dimitri Simes is the Russian-born editor of the lively bimonthly National Interest, which has recently urged trying to split apart the Sino-Russian alignment by being harder on China than on Russia. (We did the same during the Cold War.)

Simes’s policy analysis is valid but has a blot on it. The Mueller Report (pages 103-110) details how Simes arranged conferences in 2016 to put Trump in contact with the Russian ambassador and other Russians. Simes stands accused of nothing, but I suspect he’d rather not get seven pages in the Mueller Report.

Was Simes trying so hard for U.S.-Russia rapprochement that he lent himself to Russian designs? This can happen when you suppose that your agenda is fully compatible with someone else’s agenda. That can get you manipulated into serving undesired ends.