"So are we on the brink of the Second Korean War, if not the Third World War?"

Brinkmanship is back, and the world is back on the brink of war. In the 1950s the word came to be associated with John Foster Dulles, President Dwight Eisenhower’s secretary of state, who defined it as “the ability to get to the verge without getting into the war”.

In his words: “If you cannot master it, you inevitably get into a war. If you try to run away from it, if you are scared to go to the brink, you are lost.”

Brinkmanship fell into disrepute after the Berlin and Cuba crises of the early 1960s when, as far as President John F Kennedy was concerned, America and the Soviet Union came far too close to jumping over the brink into nuclear Armageddon.

Now we have come full circle. One of Eisenhower’s first steps as president was to end the Korean War. More than 60 years have passed and now President Donald Trump has summoned up the spectre of the Second Korean War.

As we have already seen in Syria and Afghanistan, Trump relishes shows of military strength. However, his use of US air power has primarily been intended to send a signal to Beijing. ...