One of the first battles in the American civil war took place near a Missouri town that it amused fate to name Carthage. Two millennia before, the Romans sacked the original, only to turn against themselves in the ensuing peace. Metus hostilis, fear of the enemy, had kept the republic together, wrote the historian Sallust, a favourite of the US founders. Without it, discord and corruption had licence to breed.
If the US is always recruiting for a Carthage (Gore Vidal referred to its "enemy of the month club") it is not because of an innate militarism. It is just that peace can be a psychic ordeal.
Without an ethnic basis, a nation can need something outside to define itself against. The civil war happened after the US trounced the closest thing it had to a local threat in Mexico. Urban strife grew between the world wars: it was armed mobilisation, not just the New Deal, that bound ethnic Italians, Poles and Irish into a civic whole.
As for the cold war, note the surge in partisanship after its end. Unanimous confirmations of supreme court nominees are one proxy-measure of a co-operative Washington. There has not been one since 1988.
An unchallenged US is a divided US. It follows that America's best hope of retaining some cohesion in the coming decades is a mighty China. What is disastrous for its relative power in the world might turn out to be a godsend for its internal cohesion. Decline has its uses.
Definition of bathos
None of the other answers to the nation’s disunity is even faintly adequate. Better-regulated social media, more competitive congressional districts: these reforms are sensible on their own terms. But the mismatch between the depth of the problem and the fiddliness of the solutions is the definition of bathos.
"Bring back weekly bipartisan Senate meetings" and "Bring back patriotic art" are other ideas that do the trivial rounds. Because they give up so much to acquire power, politicians tend to overrate how much policy can ever achieve against structural and historical forces. The US did not enter an age of discord because of some technical faults in its political system. It will not escape the mire by fixing them.
Only an external foe can do that. But not just any will do. The US requires two things of an enemy: vast scale (to induce fear) and a different model of government (for a sense of otherness). The absence of the first is why al-Qaeda turned out to be such a fleeting adhesive on US society after the September 11th, 2001, atrocities.
As lethal as it is, terror – even the word is an abstract noun – is too diffuse and de-territorialised a thing. As to the second condition, boom-era Japan, a fellow democracy, lacked it and so never crossed from daunting commercial rival to nation-binding enemy.
China scores extravagantly well on both counts. Even Americans who do not mind the loss of world primacy can object to the usurper’s political model.
It is tempting to invert the causality here. Perhaps it is not a common enemy that unifies the nation. Rather, only a unified nation can agree on a common enemy.
But recent events suggest otherwise. In his first month as president, Joe Biden has undone almost every eye-catching tenet of Donald Trump's foreign policy. The US is rejoining the UN Human Rights Council. It is open to a revival of the Iran nuclear pact, with conditions. Relations with Saudi Arabia are colder. In a virtual G7 summit on Friday, Biden will continue his rapprochement with familiar allies.
The one line of rough continuity is China. Beijing threatens to "eat our lunch", says Biden. The US faces "extreme competition". It is with China in mind that his administration is taking a protectionist line on federal procurement and mulling over a coalition of democracies.
One of the few subjects of weight on which America has cross-party agreement is China. And this is after just a few years of great-power showdown (2021 is approximately 1948 in cold war terms). If and when the US is overtaken in economic size, the sense of unity in adversity is likelier to deepen than fade.
"We are going to do a terrible thing to you," Georgi Arbatov, the Soviet adviser, is said to have told an American audience in the 1980s. "We are going to deprive you of an enemy." What a neat but desperate line it must have seemed at the time. How chillingly prescient it now reads.
If the deprivation is ending, the US stands to gain in togetherness what it loses in clout. It should not need saying which is more precious. – Copyright The Financial Times Limited 2021