Garvan Walshe is a former national and international security policy adviser to the Conservative party. He runs Brexit Analytics.

Tweet loudly, because your stick, like your hands, is so small. Were Donald Trump’s language on North Korea the product of careful deliberation, this might be the advice behind it.

North Korea’s nuclear ambitions have confounded better presidents than this orange little prince. Slowly, and despite the continual efforts of the world’s great powers, its leadership has got closer and closer to its desire: to make its vile, paranoid regime safe against all attempts to dislodge it.

Sanctions are of little use against a government that wants to cut itself off from the world. The hardships they imposed are simply passed down to a subject population. Military force was already difficult. North Korea artillery, impeccably conventional, stands ready to obliterate Seoul. Long before they built their first bomb, the Kims mastered the arts of deterrence.

Part of the problem is that North Korea is too small, and too weak, to pose an existential threat even to South Korea. Seoul doesn’t have sufficient reason to risk war through an Israeli-style strike to disarm Pyongyang’s programme.

In fact, Israel is the only country to succeed in anti-proliferation by military means. Others’ programmes, in Argentina and South Africa, expired with the oppressive regimes that sponsored them. The agreement between the P5, Germany and Iran has postponed Tehran’s bomb, with luck buying enough time for political change to take place there.

And unlike Iran, whose regional ambitions include conflict with Sunni Muslim powers across Iraq, Syria, Lebanon and Yemen, North Korea’s main objective is survival, and its acquisition of nuclear weapons defensive. From Pyongyang’s perspective they provide further protection against a hostile world than the threat to obliterate Seoul with conventional weapons can on its own. That its nuclear programme in itself provides the rest of the world with a reason to consider North Korea a threat to international peace and security will have escaped Kim and his henchmen.

Pyongyang has calculated that short of actually attacking another country with a nuclear weapon, it won’t provoke a war with the US. In this they are right, and have called the West’s bluff.

In fact they have done so for more than ten years, having first conducted a nuclear test in 2006. It’s now time to admit that the policy of preventing them becoming a nuclear state has failed, and needs to shift to protecting the region from North Korea.

A nuclear armed North Korea poses two main risks. First, that it should actually use a nuclear weapon. This requires a united response from the five officially declared Non-Proliferation Treaty nuclear weapons states that any nuclear use by North Korea will bring about immediate and devastating retaliation. Under previous US administrations, a declaration by the American President would have been sufficient. But it has become clear that North Korea believes it can ignore public threats from Donald Trump. A united front, certainly including China, and, if possible, Russia, is now required.

US proposals to try and put pressure on China by holding them responsible for North Korea’s bomb, and threatening trade sanctions are misguided. These appear far too much like an excuse for limits on trade with China the Trump Administration would like to impose anyway, and the United States currently lacks the moral authority for these measures to carry legitimacy. Worse, it is not clear that China could itself enforce a rollback of the North Korean programme without tipping that fragile regime towards collapse, and leaving Beijing and Seoul with a major political and humanitarian crisis on their borders.

The second, and perhaps more serious risk, is that North Korea continues to sell its nuclear technology to other rogue states (and possibly terrorist groups) to earn what little hard currency it can. Its successful test of a thermonuclear (that is, nuclear fusion powered) bomb carries the risk that it will seek to spread this new technology to other proliferators such as Iran and Pakistan.

It is to this risk that the International Community must turn, and step up if efforts to control the proliferation of this relatively advanced nuclear technology. In this case, the focus ought not to be on the seller but the buyer. It should consider how to devise new sanctions, designed to apply to any state, whether or not it is a signatory of the NPT, found in the future to have received thermonuclear technology from North Korea. The aim should be that they be pre-approved, so that their suspension, but not their initiation, should only be possible by an affirmative decision of the UN Security Council.

Old-fashioned international diplomacy is what this crisis needs, rather but bloodcurdling bluff from the White House is what we’re likely to get.