"If the president had his way," Kissinger growled to aides more than once, "there would be a nuclear war each week!" This may not have been an idle jest. The CIA's top Vietnam specialist, George Carver, reportedly said that in 1969, when the North Koreans shot down a US spy plane, "Nixon became incensed and ordered a tactical nuclear strike... The Joint Chiefs were alerted and asked to recommend targets, but Kissinger got on the phone to them. They agreed not to do anything until Nixon sobered up in the morning."
The allegation of flirting with nuclear weaponry is not an isolated one. Nixon had been open to the use of tactical nuclear weapons in Vietnam as early as 1954 and as president-elect in 1968 had talked of striking "a blow that would both end the war and win it". A Kissinger aide who moved over to the White House, David Young, told a colleague "of the time he was on the phone [listening] when Nixon and Kissinger were talking. Nixon was drunk, and he said, 'Henry, we've got to nuke them.' "
The 1972 election, when Nixon won his second term as president, was, as predicted, a landslide. Yet it was from the beginning a peculiarly joyless triumph, the start of an administration doomed to disaster - as the Watergate affair unravelled and many of Nixon's closest aides were either prosecuted or resigned - and culminating, eventually, in Nixon's own resignation. The firing of Haldeman and Ehrlichman, press aide Ron Ziegler, thought, was Nixon's lowest emotional moment. "He looked out of the window and said, 'Ron, it's over.' And I knew he was referring to himself and the presidency."
Nixon actually spoke of resigning in the spring of 1973, 16 months before the final fall. "Maybe," he told Kissinger during one after-dinner phone session, "we'll even consider the possibility of, frankly, just throwing myself on the sword... and letting [Vice President] Agnew take it. What the hell." Kissinger told him not even to consider it.
Nixon brought up the subject of resignation twice more in the weeks that followed, with his family. Pat urged him to fight on, as did his daughters, arguing that the country needed him. Kissinger considered what he was seeing was nothing less than "the disintegration of a government that a few weeks earlier had appeared invulnerable. The president lived in the stunned lethargy of a man whose nightmares had come true... Like a figure in Greek tragedy, he was fulfilling his own nature and destroying himself."
In June, a year to the day after the Watergate arrests, when former White House counsel John Dean was about to testify before the Senate, Nixon received the Soviet leader, Leonid Brezhnev. He had insisted on going ahead with the summit, Kissinger believed, because "to concede that his ability to govern had been impaired would accelerate the assault on his presidency". Yet the fact was, in Kissinger's view, that Watergate had "deprived him of the attention span he needed to give intellectual impetus to SALT" - the arms control talks.
"By the end of the visit," Kissinger gathered from Soviet Ambassador Anatoly Dobrynin, "the Soviet party understood that the summit had been over-shadowed by Watergate... More gravely, the summit began to convince the Soviet leaders that Nixon's problems might turn out to be terminal." This perception of US weakness at the top, Kissinger has suggested, encouraged the Soviets to risk acting as boldly as they would less than four months later, when war erupted in the Middle East. The "domestic passion play," as Kissinger called Watergate, now threatened to enfeeble the nation, not only the man.
The word circulating at the New York Times was that Nixon was seeing a psychiatrist. The therapist they had in mind was Dr Hutschnecker, whom Nixon had consulted on and off since the 50s, and reporters armed with the doctor's photograph for identification began looking for him wherever Nixon went. The Washington Star-News, meanwhile, published an extraordinary, speculative piece about what would happen if a US president became mentally ill. "What happens," writer Smith Hempstone asked, "if the president becomes physically or emotionally incapacitated and is unable or unwilling to recognise that incapacity, as might well happen in the case of a mental breakdown?... That prospect is too horrible to contemplate."
According to his biographer, Senator Sam Ervin discussed just such a possibility with majority leader Mike Mansfield before they decided on the Watergate probe. It had been, even then, "that thing which was the main fear and therefore the prime issue. Which wasn't whether or not Nixon was a crook. Millions had been talking on both sides of that issue for more than a quarter century now. Everyone knew what the prime issue was. A certain thumb moving awkwardly towards a certain red button, a certain question of sanity... Query: if the man who holds the thumb over the button is mad..."
Such fears, harboured by men not known for paranoia, were now very real. "Al Haig is keeping the country together, and I am keeping the world together," Kissinger had been heard to say as summer ended. He had recently become secretary of state and, retaining his post as security adviser, now had more independence of action than ever. Nixon did not bother to attend National Security Council meetings and would reportedly often initial documents without reading them.
On October 6 came a grave military crisis. Soviet-backed Arab armies, performing militarily better than ever before, struck at Israel and for a while it seemed they might triumph. Israel was able to contain and reverse the threat thanks to a massive US airlift, but before the guns stopped firing a moment of nuclear peril would put the entire world in danger.
Nixon did not attend a single formal meeting on the conflict during the first week of the conflict. He was clear on the essentials, Kissinger recalled, not least on the fact that a massive airlift of arms supplies was essential to Israel's survival. Yet he remained "preoccupied with his domestic scandals... deflected from details". With the successful Israeli counter-attack bringing new risks and uncertainties, Kissinger, on a trip to Moscow to negotiate a ceasefire agreement, phoned the White House on an urgent matter - only to have Alexander Haig, Nixon's chief of staff, tell him, "Get off my back... I have troubles of my own."