In his speech at Boston Cathedral last week, Barack Obama did what a responsible president should do following a terrorist attack: he channelled the public’s reaction. “We do not hunker down,” he said. “We carry on.” It was a carefully judged oration. My colleague Christopher Caldwell even described it as possibly Mr Obama’s “finest hour”. Posterity will be the judge of that. We are still in the early days of the aftermath of Boston.

Tragedies often crystallise a country’s political mood. On the upside, the Massachusetts police’s success in hunting down the culprits within four days was an extraordinary display of single-mindedness. The ending may have looked like overkill: 2,000 police surrounding a bleeding teenager in a boat. But they secured him alive and that will be invaluable. The same praise is owed to Boston’s first responders and to its public who displayed the kind of calm that makes emergencies manageable. It was one of Boston’s finest hours.

On the negative side, the broader response – and that of much of the media – highlighted the US tendency to overreact to terrorism. Since September 11, US leaders have lulled people into a false sense of security. No more attacks on the homeland, they have been promised. On the one occasion that Mr Obama suggested otherwise – “we can absorb another terrorist attack”, he said in 2010 – he was pilloried for sounding fatalistic.