Nuclear weapons deter conventional wars

There is a risk in aiming for total nuclear disarmament, because the loss of the barrier to conventional escalation will be ruinous

his month, the Treaty on the Prohibition of Nuclear Weapons will open for signature at the United Nations. Signatories will promise never to “develop, test, produce, manufacture ... possess or stockpile nuclear weapons”; never to transfer weapons to other parties nor to receive them; and never to “use or threaten to use nuclear weapons”. The treaty’s aims, if they could be universally effected, are noble. After all, the prospect of nations — including an international pariah like North Korea — facing off with their respective nuclear arsenals is horrific. Their renewed use in war would be catastrophic. But there is a risk in aiming for total nuclear disarmament, because deterring nuclear war isn’t their only legitimate use. Nuclear weapons also deter conventional war.

In recent decades, great powers have fought proxy wars, but since 1945, they have not come into direct armed conflict. Through the Cold War, nuclear weapons kept the peace in Western Europe. Only once, during the Cuban missile crisis, did deterrence come close to breaking, but the then United States president, John F. Kennedy, and Soviet Premier Nikita Khrushchev and the rest of the world learned well.

India and Pakistan have skirmished in recent decades, but the realisation that a conflict could escalate to nuclear catastrophe has contributed to the rival nations eventually standing down. The probability that Israel has nuclear weapons is the ultimate guarantor of its existence.

Since the Soviet Union’s first atomic test in 1949, the existence of nuclear weapons in many hands has not only deterred the use of nuclear weapons, but also made nuclear possessors and their adversaries think carefully about the desirability of going to war at all. When conflict has broken out, the nuclear deterrent has limited war aims to those short of total destruction of adversary nations or regime change. That’s why North Korea has sought nuclear capability so fervently.

This is the “porcupine theory”, advanced by, among others, the late strategist Kenneth Waltz: After Hiroshima and Nagasaki, many states wanted nuclear weapons, not for offensive purposes, but as a hedge against attack by other nations. It’s a good thing, then, that the United Nations nuclear treaty is probably going nowhere.

Lacking capability

For starters, the nuclear powers aren’t on board: When negotiations concluded on July 7, 122 nations voted for the treaty. But the Netherlands, the only Nato country to participate in negotiations, voted against it. As CBS News notes, none of the countries “known or believed to possess nuclear weapons” — the US, Russia, Britain, China, France, India, Pakistan, North Korea and Israel — supports the treaty. Sweden was the only country with long-standing, close ties to Nato that voted for it. Most states voting for the treaty lack the capability, or significant interest, in acquiring nuclear weapons. If the proverbial mice decide to bell the cat, success will depend upon the cat’s consent to wear a bell.

Even if the document had been perfectly drafted, and had the leaders of the effort gained a measure of buy-in from nuclear states about their interests, total nuclear abolition remains a bad idea. As former British prime minister Margaret Thatcher had said, 30 years ago, in a speech delivered in Russia:

“Conventional weapons have never been enough to deter war. Two world wars showed us that. They also showed us how terrible a war fought even with conventional weapons can be. Yet, nuclear weapons have deterred not only nuclear war but conventional war in Europe as well. A world without nuclear weapons may be a dream, but you cannot base a sure defence on dreams. Without far greater trust and confidence between East and West than exists at present, a world without nuclear weapons would be less stable and more dangerous for all of us.”

The planet would be safer with far fewer nuclear weapons, but more dangerous with none; and would be a way to prove all such weapons have been eliminated.

Some hydrogen bombs are small enough to hide in a coat closet — verification of their destruction, in the absence of a yet-to-be-determined mechanism, and in the absence of a strong international consensus, is impossible. And the loss of the barrier to conventional escalation would be ruinous. Nuclear weapons cannot be un-invented. If the treaty’s proponents had their way, the world would eventually regret it.