Editorial: 'Trump's nuclear arms missile a mistake of true magnitude'
Robert Oppenheimer, one of the fathers of the atomic bomb, said: "Any man whose errors take 10 years to correct is quite a man."
It is too early to know how many years it will take to make up for the damage done by Donald Trump's presidency, or even to carry out a full inventory of the mistakes: but one suspects his decision to pull America out of a nuclear arms control treaty with Russia will loom large among them.
This 1987 agreement with the ex-Soviet Union took a whole category of land-based nuclear missiles - those with ranges of between 500 and 5,500km - out of arsenals.
Former Soviet leader Mikhail Gorbachev - who signed the treaty with Ronald Reagan - responded to the decision succinctly: it was "not the work of a great mind".
The move may embolden Russia's President Vladimir Putin to deploy more weapons in Europe. But President Trump's 'America First' policy doesn't allow much vision for global stability or the wider implications of strategy.
Nato may similarly flex its own muscles, none of which is likely to make our planet any safer. Remember two years ago on a podium in the Rose Garden, Mr Trump startled the world by announcing the US would be withdrawing from the Paris Climate Agreement?
He dismissed the pact - signed by every single other nation on Earth - as "an agreement that disadvantages the United States to the exclusive benefit of other countries".
Now he claims to be goaded by Moscow's "flouting" of an arms agreement regarded as a cornerstone in cementing post-Cold War relationships. There is an argument that the era of bilateral arms control, involving just Washington and Moscow, may be over with Beijing now such a significant nuclear player.
The "bilateral era" might be drawing to a close, but Russia and the US still have the largest strategic arsenals; curbing them must always be a priority.
Tensions between Moscow and Washington are already strained and this can only make them more so.
Today's arms race is more crowded than ever. The world faces what has been described as a multi-polar battle for strategic and economic dominance.
Diplomats have pointed out in the past the great paradox in limiting nuclear weapons is agreements maybe don't matter in times of peace; but in times of instability they are vital.
Perhaps we should return to Oppenheimer for the final word; after all, he was a ring-master in the great death circus in which nuclear weapons were the grim stars: "The optimist thinks this is the best of all possible worlds. The pessimist fears it is true."
Whatever side one comes down on, it is the only world we have, and opening the way to more potent means to obliterate it ought not be countenanced.