EVEN for superpowers, the use of force has unintended consequences. Over the past two decades America has learned this the hard way. Its military interventions in Afghanistan, Iraq and Libya have caused devastating collateral damage. Worse, America often finds itself fighting enemies radicalised or empowered by the blowback from its own interventions. As a result, in recent years it has tried to adopt a less "kinetic" foreign policy, focused on defending a rule-bound international order.

The Avengers, a superhero organisation, have encountered many of the same problems. But they have been slower to learn the lessons. Last year Tony Stark, the billionaire military industrialist and inventor also known as Iron Man, attempted to create an automated international peacekeeping system. His well-meaning efforts led to the horrifying destruction of the Sokovian capital, Novi Grad, after the device generated an artificial intelligence bent on wiping out the human race. The tragedy this spring in Lagos, in which a number of Wakandan aid workers were killed during a counter-terrorism mission led by Steve Rogers (Captain America), was a further reminder of the dangers of allowing non-state actors with superhuman powers to enforce their own vision of international justice.

So the Sokovia Accords, under which the Avengers have agreed to accept the supervision of a UN panel, mark a major step forward. Indeed, many countries appear more eager to limit the activities of The Hulk than to limit carbon emissions. Whether the accords can be ratified in America’s divided Senate remains uncertain. But the more troubling split is the one between the Avengers themselves. While Mr Stark advocates that the group sign the accords, Mr Rogers refuses.

Institutional constraints on superhero activity have been controversial ever since 1977, when America’s Keene Act took up the question of who would watch the Watchmen. The X-Men faced severe discrimination under the Mutant Registration Act, and the Incredibles long chafed under the oversight of the National Supers Agency. Last year Batman and Superman came to blows over similar issues of accountability.

Superheroes, like most elites, are instinctively hostile to regulation, and Mr Rogers’ leeriness is exacerbated by his deep-rooted cultural nationalism. It is hardly surprising that a superhero named Captain America would be allergic to what George Washington called "foreign entanglements". Moreover, Mr Rogers has a point when he argues that the UN is a politicised body that may bicker over granting permission to intervene until it is too late. Rivalry between UN members has paralysed the international community during bloody crises from Bosnia to Syria.



The question, however, is whether superheroes or superpowers do better without such constraints. In fact, they do worse. As America learned in Iraq, and as Mr Stark learned in Sokovia, people without procedural oversight are apt to be led disastrously astray by their own biases. Mr Rogers’ mistrust of institutions, like that of the leaders who launched the Iraq war, is linked to a hubristic faith in his own moral righteousness: he believes that the world is divided into good guys and bad guys, and that he knows who is who. In real life, nothing is so simple. No one ever has perfect information, different people may have legitimate but conflicting claims to justice, and no one’s motives are entirely transparent, even to themselves.

It is because of the imperfection of humans (and superhumans) that we need laws and institutions. As Captain America should know, this recognition lies at the heart of his country’s political philosophy: to paraphrase Madison, “If superheroes were angels, no government would be necessary.” The Avengers are no angels. They should accept the Sokovia Accords.