It is almost exactly 55 years since the world teetered on the brink of Armageddon, as the US and Soviet Union, the world’s biggest nuclear powers, faced off in the Cuban Missile Crisis.
American and Russian fingers twitched over the launch buttons of intercontinental ballistic missiles.
Had either side blinked and fired, the world could have become a nuclear wasteland.
There is an ominous sense of déjà vu in the latest case of nuclear brinkmanship between the US and North Korea.
Pyongyang has built and tested intercontinental missiles and, more frightening, has just successfully tested a hydrogen bomb, many times more powerful than the ones which destroyed two cities in Japan in 1945.
Threats of sanctions appear not to have deterred the North Korean leader, Kim Jong-Un, from pursuing his nuclear ambitions, which seem to include threatening mainland America.
At the same time, a belligerent President Donald Trump is not helping with his sabre-rattling.
A big question is: How would the nations of the region – including nuclear superpowers Russia and China – react if the US chose the military option?
A maverick dictator with nuclear missiles is not good for the world…but neither is an imperial reaction from a superpower. Calm heads are needed all round.