Less than halfway into the 20th century, Henry Luce wrote an essay for Time, the magazine he founded, and headlined it The American Century. It sounded presumptuous and bombastic, and it was widely resented, most keenly by those who never read a line of it. What had America given the century except Tin Pan Alley, Hollywood, Al Capone and the hamburger? Luce, in truth, had written a critical essay, not one of celebration. He was bemoaning the fact that America had failed to realise its glittering potential. Americans were "nervous or gloomy or apathetic", unhappy because they had been unable to accommodate themselves spiritually and practically to the reality that they had become the most powerful nation in the world.
They had muscle, but no moral will. They were not throwing themselves with joy and gladness into spreading the ideals of civilisation, of justice, truth and charity, "lifting the life of mankind from the levels of the beasts to what the Psalmist called a little lower than the angels".
Luce was writing in 1941 - before America's entry into the second World War, before the victory on the battlefields of the Alliance it came to lead, before the Marshall Plan, before the rebuilding of Europe and Japan, before the long ordeal of the cold war, before the collapse of the Soviet Union - before a series of triumphs, I would argue, that make Luce's headline premature but prophetic.
It all seems inevitable now, but judgment has to begin with Frederic Maitland's dictum: "It is very hard to remember that events now long in the past were once in the future." Luce flew in the face of the isolationist sentiment still prevalent in America even as island Britain stood alone against Hitler. It was espoused by America's great folk hero Charles Lindbergh, and John Kennedy's father, and Henry Ford, and the chairman of Sears Roebuck, and the demagogic Father Charles E. Coughlin, with his millions of devotees, and high-powered Senators both Democratic and Republican.
The historian John Chamberlain spoke for them all in deriding the whole idea of America making a commitment in idealism. It was "straight-line Prometheanism". Americans, he wrote, were not so heroic. Luce's programme required a faith that "can only be sustained for short periods"; and since people are not normally Promethean in large numbers, Luce's programme must, in ordinary times, fall into the hands of hypocrites skilled in using great slogans for nefarious purposes. An interventionist America might well degenerate into "an imperialism that will fail in liberality and become something close to the Nazi thing".
The Nazi comparison sounds absurd now, but Chamberlain wrote without knowledge of the Holocaust - and the balance of history was overwhelmingly on his side. Why should America be immune to Acton's law that power tends to corrupt and absolute power corrupts absolutely? It would be disingenuous to suggest it escaped altogether.
McCarthyism was the use of great slogans for the nefarious silencing of dissent. The ill-judged intervention in Indochina begun by President Kennedy, accelerated by Lyndon Johnson and painfully relinquished by Nixon was a close run with imperialism; so were the CIA coups in Chile, and Iran, and Guatemala, the sabotage in Cuba, and the readiness to countenance brutalities in Central and South America whenever some banana republic colonel told Washington his critics were all Commies.
President Eisenhower was none too soon in his valedictory warning of the military-industrial complex menace to democratic government: only in recent years has it been revealed that the US army and the Atomic Energy Commission poisoned thousands of Americans downwind of the 126 atomic bomb tests, and untold numbers elsewhere, then lied about it for decades to avoid just claims for compensation for injury and death.
These are grave failures, but in the final analysis they are crevices the climber stumbled into on the ascent of Everest: blunders and moments of peril to be examined and understood and regretted, but suggestive also of the stupendous nature of what was attempted and what was achieved. The flag planted on the summit marked nothing less than the survival of Western civilisation.
Yes, it is of note that in only its second century the United States became the world's leading economic, military and cultural power. Yes, it is remarkable that in this short period it did not merely double or triple the wealth of its citizens but increased their well-being five times over, so that they came to enjoy a standard of living and an expectation of life heretofore unknown in the history of the world. But none of this adds up to a decisive claim on the century. The glory of a people does not lie in their economic indices, their actuarial tables or even the fame of their designer jeans; it lies in their idealism, in the use they make of their resources, in the kind of people they become amid the temps of pride and greed.
In the 20th century, the essentially isolationist American people did more than grow rich and expand their domestic freedoms, despite McCarthyism and racism. They sustained Western civilisation by acts of courage, generosity and vision unparalleled in the history of man. One can argue endlessly about America's cultural and commercial influence. Is the world a duller place because there are Macs in Moscow, jeans in Jaipur, Coke in Chile? Have vacuous sitcoms and tyre-squealing movies corrupted values and killed native talent? Doesn't American education suck? Isn't American business ruthlessly unfair? What the hell are they doing to the language? Yes, no, and maybe, and yes and no again; mix according to taste. But there can be no equivocation about America's defence of freedom. The second World War would have been inevitably lost if America had stayed aloof. Traditional isolationism would have bequeathed the planet to a genocidal totalitarianism.
The Nazi extermination of six million Jews, Gypsies, Slavs and Poles, and Japan's more or less systematic decimation of the Chinese, Filipino and Korean peoples, and their live medical experiments on human beings, were grim portents for the African, Arabic and Indian nations. Their peoples were even more despised by the Axis's racial supremacists. Sustained by slave labour and murder, by sophisticated modern weaponry, by the technologies of surveillance, and possessed of the moral sensibilities of a tapeworm, the New Order would have perpetuated a long dark night of the soul. One need only look at the rigid social systems, the inhuman scale of the architecture, the bombastic ceremonies, the flaccid and constricted art that the dictators so relentlessly promoted, to glimpse what would have been built on the ashes of Western civilisation.
As it was, the second World War was the overwhelming event of the century, indeed the greatest single tragedy in the history of mankind. More than 50 million people lost their lives, perhaps 20 million of them civilians.
Whole populations were uprooted from their homes and countries, millions of families ripped apart. It is true that the army which did more than any other to defeat Hitler was the Red Army. The German Army and the SS spent 7,146 divisional combat months on the eastern front, but only 1,121 in Africa, Italy and north-west. But if the Red Army did more than any other single force to crush Hitler it was in the service of a dictator every bit as murderous; and Stalin himself conceded that Russia would have been vanquished if it had fought without American military production: The Red Army marched in American boots.
But America did not simply lead the Allies to victory in the second World War. That was only a prelude to even greater things. Good and bad nations have won and lost wars for centuries. What was unique about America was what it did after the last shot had been fired.
By 1950, America had committed itself to a global role unimaginable even three years before, nothing less than the creation of a new liberal world order based on freedom and respect. No design has been nobler in conception or more brilliant in execution than the complex of international organisations for economic welfare, education, collective security and human rights that America nourished in the second half of the century. No victorious power has treated its vanquished enemies as America came to treat Germany and Japan, two nations that had cost the lives of hundreds of thousands of American servicemen. The fates of the peoples conquered by the Soviet Union and the Americans and their allies could not have been more different. The 20 million Germans in the Soviet Zone (later Eastern Germany) exchanged one yoke for another. The 40 million in the west found restored in full measure the freedom they had lost in 1933, and America gave to the Japanese a freedom they had never known.
The Soviets seized factories and deported skilled workers. Their claims for reparations (from all zones) were not unreasonable, considering the damage they had suffered, but in both Germany and Japan the Americans were net givers, not takers. The Germans lucky enough to be occupied by the Allies got the billions of the Marshall Plan; with the impetus of the Korean War (where America again made a sacrifice for freedom), the Japanese got about as many dollars. American experts taught their ex-enemies the techniques of mass production that had assisted their defeat. The Soviets everywhere installed secret police.
In Japan, almost the first action of General Douglas MacArthur, the Supreme Commander of The Allied Powers, was to dismantle the secret police. The Soviets jailed opponents of Communism - and executed non-co-operative Communist leaders. In Japan, the conservative MacArthur freed Communists and socialists from prison. The Soviets rigged elections and controlled the press and trade unions. In Germany, having purged the Nazis, America swiftly restored democracy and free speech from the ground up. In Japan, the new constitution America introduced within a six-day span gave the people a bill of rights, including freedom of the press and of assembly, an independent judiciary and freedom to bargain collectively for wages. The constitution also guaranteed equal rights for women - a clause still absent from the constitution of the United States itself. The critics, left and right, have argued that all this in Europe and Asia was done cynically to provide customers for America's market-hungry industries. Of course, in pressing for free trade and restoring the world economy, America was pursuing its enlightened self-interest. And why not?
But that is not all there was to America's new role. The insistence of successive administrations on greater European co-operation was not to America's obvious economic advantage, nor was the rebuilding of Japanese steel, shipping and car industries. The criticism altogether ignores the force of moral idealism in America. It ran deep among the increasingly prosperous American taxpayers who footed the bills. It still does.
The idealism offended some people in Europe when it took the form of a crusade against Communism. Ideology supplanted pragmatism and many errors were made. The red hand of the Kremlin was seen in every nationalist movement, with fatal consequences. The political containment of the Soviets, advocated by the State Department's guru, George Kennan, was transformed into a costly military containment. It diverted resources from world recovery, and the anti-Communist hysteria fomented by a misreading of Kennan threatened civil liberties. He assessed the consequences in an article in 1995: "We paid with 40 years of enormous and otherwise unnecessary military expenditures. We paid through the cultivation of nuclear weaponry to the point where the vast and useless nuclear arsenals had become (and remain today) a danger to the very environment of the planet. And we paid with 40 years of Communist control in Eastern Germany, Czechoslovakia and Hungary. We paid all this because we were too timid to negotiate."
Kennan's criticism merits respect. But America did not, in the end, pay for the Cold War by sacrificing its values to its fears. It defended them with its faith. It emerged from the tribulations of the 1950s a stronger and freer society. And the fact remains that the triumph of liberal democracy over the Communist totalitarianism was a pinnacle of the American century.
It would be a conceit to claim the collapse of the Soviet Union as wholly an American triumph. Many hands tore at the Berlin Wall, including those of the European democrats, Pope John Paul II, the dissidents, the American trade union movement, the last leader of the Soviet Union, the reforming Mikhail Gorbachev - and, one might add, the first leader, Lenin, who laid the foundations of a society that was bound to collapse of its own deadweight.
No single brow will probably ever be able to claim the wreath of victory over that dangerous and depressing totalitarianism. But there can surely be no doubt that, in its spiritual as well as its material beneficence, the American example was, in the long dark years, the torch of freedom all the world could see.
We should pray that freedom flames as brightly in the unpredictable gusts and gales that lie just around the corner in the new millennium.
Harold Evans is author of The American Century, which will be re-issued in paperback in November by Pimlico (£25 in UK); vice- chairman and editorial director of The Daily News, US News and World Report and Atlantic Monthly and former editor of the Sunday Times (1967-1981).