The biggest rap against Barack Obama’s foreign policy is that he is naive. Yet, as his presidency matures, Mr Obama is showing qualities one would normally associate with Henry Kissinger — the arch-realist of US diplomacy. Neoconservatives and liberals alike care about the internal character of regimes with which the US does business. Mr Kissinger stands apart from that tradition. The less Mr Obama preaches morality to foreigners, the more he distances himself from the exceptionalists — the more opportunities he creates. It is a welcome sign of a president with a learning curve.

The chief example is Mr Obama’s evolution on the Middle East. In 2009, he went to Cairo to offer a new chapter in relations between the west and the Muslim world. His felicitous words went down well in the region but were quickly forgotten. Today Mr Obama gives fewer speeches but has a bigger appetite for deeds. The best measure is his recent framework nuclear deal with Iran. Much to the chagrin of his critics, the agreement is silent on Iran’s sponsorship of terrorism abroad and repression at home. Its focus is on curtailing Iran’s nuclear ambitions.

There is no mention of Iran cutting off its support for the Houthi rebels in Yemen, or recognising Israel’s right to exist. That is just as well. Had Mr Obama insisted on either, there would have been no deal (there is still a way to go before reaching a final agreement). In pushing ahead anyway, Mr Obama is grasping the essence of diplomacy — when adversaries come to terms, neither achieves everything they want. Much the same would apply to Mr Obama’s recent deal with Cuba’s dictatorship. Although Mr Kissinger has criticised Mr Obama’s Iran deal as too weak, it is very much in line with his school of diplomacy. The perfect should not be the enemy of the good.