Known unknows

Tony Blair's announcement of "the Government's decision to maintain the United Kingdom's independent nuclear deterrent" is an intriguing portent of the arguments we can expect to be made in defence of the Trident renewal in the run-up to next year's Parliamentary "debate" on the matter.

Blair's key argument (there are others, but they all seem to come back to this starting point) fixates on the fact that the post-Cold War era is one "of unpredictable but rapid change": "Anyone can say that the prospect of Britain facing a threat in which our nuclear deterrent is relevant, is highly improbable. No-one can say it is impossible." Anything could happen in the next forty-five minutes: terrorists might try to hide a nuclear bomb in Tony's toilet; North Korea might try and impress people with how big its missile is; Jacques Chirac might decide he's had enough of the Rosbifs:

It is written as a fact by many that there is no possibility of nuclear confrontation with any major nuclear power. Except that it isn't a fact. Like everything else germane to this judgment, it is a prediction. It is probably right. But certain? No, we can't say that.

Given this all pervading uncertainty, we are compelled to maintain our nuclear "deterrent" in order that we are ready to deal with any conflicts which may arise.

This argument consists of two premises: (1) we can't be sure what the international security situation will be in the future; and (2) we need to maintain our nuclear "deterrent" so that we're ready in any eventuality. The first premise is an indisputable statement of fact, but the second - essentially a statement of opinion - is dubious at best.

Let's try playing out Blair's argument with a different case study: "Anyone can say the prospect of Britain facing a threat in which a big gun for shooting down alien space ships would be relevant, is highly improbably. No-one can say it is impossible." The first premise may now look sillier, but remains just as true. We can't be sure that we won't be invaded by Brain Eating Bug Eyed Monsters From Uranus, even if it is pretty unlikely. Does if follow that we are compelled to develop a big gun for shooting down alien space ships? I think not. Investing billions in hugely dangerous technology needs to be justified on the basis of something more substantial than vague hypotheticals.

In fact, the very real uncertainty of the modern epoch can be wielded, at least as convincingly, as an argument against nuclear weapons: "Anyone can say that the prospect of a British nuclear submarine being hijacked by terrorists in order to attack British cities, is highly improbable. No-one can say it is impossible." The best way to prevent such an eventuality is to start decommissioning our nuclear arsenal as soon as possible. A terrorist armed with a chunk of circuit board is a rather less bothersome prospect than one armed with a submarine full of fully-functioning nuclear missiles.

On some level, I think Blair is aware of the weaknesses of his argument. At one point he remarks, without further comment, "[Trident] is also our only deterrent. In the 1990s we moved to Trident as our sole nuclear capability." If uncertainty is the key justification for maintaining our "deterrent," because we can't know what threats we may face, then logically we should surely try to prepare for hypothetical threats which can't be confronted by submarine-based missiles. By this logic, making Trident "our sole nuclear capability" was surely a mistake which needs rectifying. Of course, Blair doesn't suggest this because he doesn't believe uncertainty should guide policy, rather he's using it as an excuse for a policy he's already set his mind on.

As I hope is obvious from the foregoing, uncertainty alone is a bad basis for policy making. Essentially it leaves you with an argument for doing both everything (because if we don't we may regret it) and nothing (because if we do we may regret that as well). At the very least, you have to make some attempt to assess the likelihood of various threats. If we do this in a sober manner I think the arguments for renewing Trident are weak. There are plenty of non-nuclear states which manage to get from one day to the next without being wiped off the face of the earth. What makes us think we're any different? Sure much of the world is pissed off at us about Iraq, but few of them have nuclear weapons and in any case it would be easier, cheaper and better all around to get out of Iraq. But then, maybe it is in Iraq that we begin to get an insight into what our nuclear "deterrent" is really about.