THE first Tuesday in November, every four years, is an important date for all countries of the world because it is then that the most powerful of them, the US, elects its president. This man (never yet a woman) will, to a greater or lesser extent, affect the lives of each one of us so long as his term of office lasts, and sometimes beyond that.

So defined, it is an event of universal importance. Few foreigners felt happy with the election of Donald Trump in 2016, but we have learned he is not to be taken for granted. In 2020, none of us know much about his opponent, Joe Biden, but that in itself is good reason to be cautious.

For a start, American elections can to foreigners seem strangely parochial in nature. Often, the presidential campaigns will have been conducted with little reference to anything that has happened or might happen outside the US.

The American people are great travellers, yet they seem to believe their passing presence overseas is an opportunity for teaching rather than for learning. We foreigners, on the other hand, tend to regard this frame of mind as naive, and occasionally even dangerous.

Whatever the differences of opinion, they represent to some extent one major historical fact. The American republic represented the first serious attempt by the human race to set up an ideal form of government.

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In 1776, the date of the Declaration of Independence in Philadelphia, there had already been societies that prided themselves on their respect for rationality or their enjoyment of divine favour. But none of these forebears grew out of a conviction that the human race could build a system of government that would itself summon them to a higher destiny.

The American Revolution was, in other words, a product of the Enlightenment, a period when the most perceptive Europeans sought to discern the principles that would make life good or bad for individual men and women. Then rules might be deduced by which society could regulate itself. But the Europeans disposed to act in this way often experienced more trouble and strife than peace and quiet. The burden of history was too heavy.

Only the Americans, after removing themselves to another continent, found there the chance to launch a great social experiment, the erection of a perfect republic. They did make mistakes but, more than two centuries on, we can fairly say the project has been on the whole successful, and in its particular parts as well as in its conceptual whole.

The constitution that the original 13 states gave themselves in 1788 is still in good working order, still the subject of lively intellectual debate at home and round the world, still an example of happiness and prosperity for hundreds of millions of people. It has undergone only a limited number of amendments. The triple structure of executive, legislature and judiciary, each a check and balance on the other, remains in vigorous force. The liberties of Americans are taken seriously and remain the foundation of public life.

Of the constitution’s flaws, on the other hand, the worst has been that it scarcely addressed one feature built into American society almost since its origins, after the first black slaves were sold in Virginia in 1619.

Africans were not the only ones to be enslaved, in their case after being abducted across the ocean. But their special fate was to create social problems never fully solved, even after the abolition of slavery itself.

In 2020, the worst conditions for black people are still a standing rebuke to the underlying humane and liberal spirit of America. They have tainted the whole history of the republic. The Founding Fathers’ achievement led in less than a century to the Civil War. Even the price it exacted in lives and resources brought nothing like equality to the liberated black population.

Not till quite recent times did the republic set out to endow all its citizens with the rights written into their constitution. And the task has not been completely fulfilled today, after the election of the first black president.

YET the historic vices of the US are still not enough to negate its virtues. In the period since 1945, when the republic has stood at the peak of its power, it has dominated the globe in both a political and an economic sense.

In other continents there have indeed been alliances not controlled by the Americans, but none that has decisively countered the Americans. One reason is that, for all its idealism, the US often resorts to brute force to get its way.

A republic that countenances both wealth and violence has by means of both also become the mightiest global economic power. It has done so through the success of the capitalist system, which it adopted early and is still consolidating.

Possible alternative structures, usually conceived of as socialism of some kind, never had the better of rivalry that at length led to decay and collapse. This did not mean capitalism was problem-free, and advanced thinking about the prevailing economic system remains a prominent feature of America’s intellectual life. But hardly anybody thinks there is ever going to be a different system.

Through these means, the republic had by the end of the 20th century created a world largely in its own image. Yet today we have to ask whether, for all its might, this American power has centred on its decadence. New economic rivals have arisen – notably China, which the US cannot be certain of outdoing in the way it so easily outdid the Soviet system.

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Little apparent value is attached to old alliances that might at least prove useful in the novel circumstances, such as those in Latin America. The thought strikes that every country in the world with an American alliance (except Israel) needs to take a long, hard look at it.

That is true of the UK, too. In the past we have often spoken of a special relationship with the US. During the Second World War, the two English-speaking combatants had to work hard to pursue common goals, even against a common enemy. Getting closer to the Americans did not always strengthen the UK’s hand.

Still close to our old allies today, we are all the same no longer so strong, and Trump is hardly in the business of doing us favours. As we negotiate with him on trade, for example, we hear more about the concessions he wants than about the preferences he might offer.

That is only to be expected when one side is in the mood to flaunt its strength while the other is worried about the weakness of its international stature.

If Trump is defeated at the polls today and Biden is by tomorrow the clear winner, it will signal something like a return to normality. Still, four years of a less benign and more ruthlessly self-interested America will have reminded us this normality is not as robust as it used to be.