Donald Trump is right about North Korea, of course. It never made sense for the US to launch a “bloody nose” military strike against Kim Jong Un’s isolated country without having tried diplomacy first.

America and North Korea were on a collision course to war. A unilateral US attack, which had been considered seriously in Washington for months, would have brought with it incalculable risks. The powerful North Korean military would probably have struck back. China might have intervened to defend its border, producing a potential stand-off between Beijing and Washington. US military leaders predicted such a clash would cause tens of thousands of casualties in both South and North Korea. It could have been catastrophic for Mr Trump to choose war before talks on a bitterly divided Korean peninsula.

Sitting US presidents and North Korean leaders have not spoken in seven decades. The only American known to have met Mr Kim is the retired basketball star Dennis Rodman, an athlete of considerable merit but decidedly not the person to negotiate the future of a nuclear crisis. However abruptly Mr Trump has cast aside decades of American policy and his own opposition to talks, he has chosen the wiser path for his country and the world. Better he meet Mr Kim in an extraordinary summit than march off blindly to war.