There are many influential supporters of nuclear war, and some of these contend that the use of ‘low-yield’ and/or short-range weapons is practicable without the possibility of escalation to all-out Armageddon. In a way their argument is comparable to that of the band of starry-eyed optimists who thought, apparently seriously, that there could be such a beast as a ‘moderate rebel’.

In October 2013 the Washington Post reported that “The CIA is expanding a clandestine effort to train opposition fighters in Syria amid concern that moderate, US-backed militias are rapidly losing ground in the country’s civil war,” and the US Congress gave approval to then President Barack Obama’s plan for training and arming moderate Syrian rebels to fight against Islamic State extremists. The belief that there could be any grouping of insurgents that could be described as “moderate rebels” is bizarre and it would be fascinating to know how Washington’s planners classify such people. It obviously didn’t dawn on them that any person who uses weapons illegally in a rebellion could not be defined as being moderate. And how moderate is moderate? Perhaps a moderate rebel could be equipped with US weapons that kill only extremists? Or are they allowed to kill only five children a month? The entire notion was absurd, and predictably the scheme collapsed, after expenditure of vast amounts of US taxpayers’ money.

And even vaster amounts of money are being spent on developing and producing what might be classed as moderate nuclear weapons, in that they don’t have the zillion-bang punch of most of its existing 4,000 plus warheads. It is apparently widely believed in Washington that if a nuclear weapon is (comparatively) small, then it’s less dangerous than a big nuclear weapon.

In January 2019 the Guardian reported that “the Trump administration has argued the development of a low-yield weapon would make nuclear war less likely, by giving the US a more flexible deterrent. It would counter any enemy (particularly Russian) perception that the US would balk at using its own fearsome arsenal in response to a limited nuclear attack because its missiles were all in the hundreds of kilotons range and ‘too big to use’, because they would cause untold civilian casualties.”

In fact, the nuclear war envisaged in that scenario would be a global catastrophe — as would all nuclear wars, because there’s no way, no means whatever, of limiting escalation. Once a nuclear weapon has exploded and killed people, the nuclear-armed nation to which these people belonged is going to take massive action. There is no alternative, because no government is just going to sit there and try to start talking with an enemy that has taken the ultimate leap in warfare.

It is widely imagined — by many nuclear planners in the sub-continent, for example — that use of a tactical, a battlefield-deployed, nuclear weapon will in some fashion persuade the opponent (India or Pakistan) that there is no need to employ higher-capability weapons, or, in other words, longer range missiles delivering massive warheads. These people think that the other side will evaluate the situation calmly and dispassionately and come to the conclusion that at most it should itself reply with a similar weapon. But such a scenario supposes that there is good intelligence about the effects of the weapon that has exploded, most probably within the opponent’s sovereign territory. This is verging on the impossible.

War is confusing in the extreme, and tactical planning can be extremely complex. But there is no precedent for nuclear war, and nobody — nobody — knows for certain what reactions will be to such a situation in or near any nation. The US 2018 Nuclear Posture Review stated that low-yield weapons “help ensure that potential adversaries perceive no possible advantage in limited nuclear escalation, making nuclear employment less likely”. But do the possible opponents of the United States agree with that? How could they do so?

The reaction by any nuclear-armed state to what is confirmed as a nuclear attack will have to be swift. It cannot be guaranteed, for example, that the first attack will not represent a series. It will, by definition, be decisive, because the world will then be a tiny step from doomsday. The US nuclear review is optimistic that “flexibility” will by some means limit a nuclear exchange, or even persuade the nuked-nation that there should be no riposte, which is an intriguing hypothesis.

As pointed out by Lawfare, “the review calls for modification to ‘a small number of existing submarine-launched ballistic missile (SLBM) warheads’ to provide a low-yield option.

It also calls for further exploration of low-yield options, arguing that expanding these options will ‘help ensure that potential adversaries perceive no possible advantage in limited nuclear escalation, making nuclear employment less likely.’ This is intended to address the argument that adversaries might think the United States, out of concern for collateral damage, would hesitate to employ a high-yield nuclear weapon in response to a ‘lower level’ conflict, in which an adversary used a low-yield nuclear device. The review argues that expanding low-yield options is ‘important for the preservation of credible deterrence,’ especially when it comes to smaller-scale regional conflicts.”

“Credible deterrence” is a favourite catch-phrase of the believers in limited nuclear war, but its credibility is suspect. Former US defence secretary William Perry said last year that he wasn’t so much worried about the vast number of warheads in the world as he was by open proposals that these weapons are “usable”. It’s right back to the Cold War and he emphasises that “The belief that there might be tactical advantage using nuclear weapons – which I haven’t heard being openly discussed in the United States or in Russia for a good many years – is happening now in those countries which I think is extremely distressing.” But the perturbing thing is that while it is certainly being discussed in Moscow, it’s verging on doctrine in Washington.

In late February US Defence Secretary Esper was reported as having taken part in a “classified military drill in which Russia and the United States traded nuclear strikes.” The Pentagon stated that “The scenario included a European contingency where you’re conducting a war with Russia and Russia decides to use a low-yield, limited nuclear weapon against a site on NATO territory.” The US response was to fire back with what was called a “limited response.”

First of all, the notion that Russia would take the first step to nuclear war is completely baseless, and there is no evidence that this could ever be contemplated. But ever if it were to be so, it cannot be imagined for an instant that Washington would indulge in moderate nuclear warfare in riposte. These self-justifying wargames are dangerous. And they bring Armageddon ever closer.