Richard Milhouse Nixon: The invincible quest, by Conrad Black

In official biographies and in unofficial ones penned posthumously by ardent admirers, it is usual for the subject to appear indubitably in the right. Not so here. Although the late President Nixon is clearly one of Lord Black's great heroes – surpassed among recent American leaders "only by Roosevelt, Kennedy and Reagan, and equalled only by Clinton" – this 1,152-page work doesn't skirt Nixon's frailties, craftiness, venality, maladjustment, mawkishness and mania.

There are countless politicians who shock us with the deadness of their souls to all the higher emotions; who care for nothing in the world except the grinding of their own axes. Occasionally they slip and fall upon the whetted blade, as did Nixon after the Watergate scandal of 1973. It has been said that the greatest politicians have neither morals nor malice in their composition (probably an exaggeration), and that the outrageous charges they make against one another are intended only for public consumption and credulity; the hatreds of political opponents, like their occasional ebullitions of bonhomie, being shallow-rooted plants. Nixon's composition was somewhat different.

As a boy, Nixon "never misbehaved in the presence of adults". The face he presented to his peers was soft, shy and squishy, obscuring a resolve hard and unyielding; much like a plum, which was his wife Pat's nickname for him in later years. Others preferred to call him "Tricky Dicky", as befits the guy who said: "You've got to be a little evil to understand those people out there. You have to have known the dark side of life."

Black begins by describing his hero as "one of America's greatest political leaders" as well as being "probably its most controversial president." He concludes: "In the years since his death [in 1994], his legend seems to have grown more quickly than his memory has receded. Richard Nixon will linger in the American consciousness for a very long time."

We are, as Goethe says, connected with our century by our defects. Nixon was well supplied with these: rarely at ease, making others jittery, paranoid (though Black challenges this), mendacious (which Black allows), ruthless, "unseemly", tending to sweat under intense lighting, a "rank opportunist", a "wary pugilist" who suspected virtually everyone around him. On the other hand, he was blessed with "a sonorous and versatile voice", shrewdness, a terrific memory and tireless political ability.

It is hard to know whether Nixon was a creature of those fearful post-Second World War years of anti-Communist hysteria and the House Un-American Activities Committee (HUAC), or was largely responsible for engendering the former and placating the latter. Despite his high regard for Nixon, Black pulls no punches in ridiculing Nixon's lies as a Red-hunter and those of his ally, FBI director J Edgar Hoover, in attempts to subvert due process. He also pours scorn upon "the nasty little elves" of HUAC.

The book is an attempt to press forward with a desire in many American quarters to rehabilitate the disgraced president, particularly because of what is increasingly regarded as his inspired diplomacy towards China, culminating with a visit to Beijing in 1972. That aside, it is a very valuable, detailed and reasonably balanced chronicle of 20th-century American politics. Recently opened tape-recordings and documents have enabled the author to paint a cool, informative portrait of both Nixon Agonistes and America Perplexus. It is less stylish than Black's excellent 2003 biography of Franklin Roosevelt, and sometimes monotonously arranged (writing about Pat Nixon, Black begins four consecutive sentences with " She").

My own period as a correspondent in the United States began with Nixon's election to the White House in 1968. It more or less concluded with the Watergate affair (the White House cover-up of a break-in at the Democratic National Committee's Washington headquarters) and a book about it by me and three colleagues. Watergate forced the president to resign in August 1974. It is fair to say that a vigorous anti-Nixon bias prevailed through most of his presidency, largely due to the war in Vietnam and the bombing of Cambodia, but partly due also to a failing relationship with the US media, which often indulged in much that was bloat, gloat or unworthy of note. These two elements were chiefly responsible for casting a dark shadow around Nixon's positive achievements. It is that shadow which Lord Black seeks to dispel. "Nixon inherited a hopeless war," he says in exculpation. And "most of the vast Watergate literature is self-serving claptrap." Indeed, the Woodward and Bernstein book, All the President's Men, he describes as "pretty far-fetched", while their next one The Final Days, an account of Nixon's fall, is "an outrage".

Among the author's many well-placed informants is Henry Kissinger, Nixon's national security adviser and later his Secretary of State. Their relationship was, to say the least, tense. Nixon described Kissinger as "Machiavellian, deceitful, egotistical, arrogant and insulting". According to Black (a former business associate of Kissinger), after Nixon's resignation the two "were in a historical wrestling match".

Nixon's tenure is generally characterised as incalculable, untrustworthy and disturbing. Lord Black doesn't quite undo that picture. What he does is satisfy his readers that the presidency demands either a rare moral elevation that is unconscious of the whips and scorns of office, or a hard integument that is impervious to them. A president is most successful who has the fewest scruples, and his principles must hang about him, in Falstaff's phrase, "lightly, like an old lady's loose gown".

Nixon was not overburdened with scruples, and, even in these pages, alternates between hard boozing and tantrums, and between being " perfectly clear" (his own overused cliché) and being sincerely cynical (in fact as well as in form). But he was far too buttoned-up, even from boyhood, to let whatever principles he had hang out. Despite Conrad Black's research and opinion, it may be a touch premature to proclaim tout savoir, c'est tout pardonner.

Scruples cause one to consider the propriety (or legality) of one's actions. Those of the author – or the alleged absence of them – have come under judgement by a Chicago jury whose recent verdicts, that he was guilty of fraud and obstruction of justice, have coincided with the publication of this book. In describing the case against him (the result of which he is expected to appeal), as "an outrage", Black displayed a conviction comparable to Richard Nixon's magnificent televised protest: "My fellow Americans, I am not a crook!" Gainsaying, one must accept, is a constant runnel of history. *

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