Jeffrey Goldberg’s brilliantly composed portrait of Barack Obama’s foreign policy mindset in the The Atlantic is a landmark achievement. It also helps to explain why the US is today a halting and uncertain power in global politics.

Mr Obama will leave office with important international achievements in place, among them the Iran deal, a historic climate change pact and the Asia and Europe trade agreements. He has also conducted himself with grace and dignity in office.

The US president was right to focus his conversations with Mr Goldberg on perhaps the most difficult question in American foreign policy: when should presidents order the military to intervene in wars beyond our borders and when should they not? In doing so, however, he seems determined to contest principles that recent presidents have found vitally important in the exercise of American power. Here is where the emerging “Obama Doctrine” often comes up short.