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Q&A: Des Browne on the UK’s Decision to Increase the Cap on Nuclear Warheads

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In March, the United Kingdom government made a surprise announcement in its Integrated Review that it would increase the cap on its overall nuclear weapon stockpile while no longer publishing details of its nuclear stockpile and missile numbers. The Integrated Review also appeared to expand the number of scenarios where the UK would consider using nuclear weapons. These decisions shocked many nuclear observers who noted that for decades the UK had been focused on reducing the role of its nuclear arsenal.

To further break down the announcement, I spoke with Des Browne, vice chair of NTI and former UK Secretary of State for Defense. A lightly edited transcript of our conversation is below:

Did these decisions come as a surprise to you?

Unequivocally, yes. They came as a surprise to everyone. There was no sign of them. The government came to power with a manifesto pledge to have an integrated review of foreign, defense, and development policy that would deal with the criticism leveled at previous reviews that they were driven by the Treasury and consequently, either were too restrictive or too ambitious. In general, they did a good job. It was due to report in July 2020 but was delayed because of COVID. I think that’s important. It was supposed to come out when the Trump Administration, an administration that had a similar approach to increasing the role of nuclear weapons, was still in power. But it got delayed until the Biden Administration, which has an ambition to reduce, not increase, the salience of nuclear weapons in strategic defense.

The Biden Administration also aims, in consultation with allies, to consider a declaratory policy of “sole purpose,” that nuclear weapons are solely to deter nuclear attacks against the U.S. and its allies. The UK basically had a “sole purpose” policy without ever explicitly saying so. Now it has rolled back that policy without any apparent consultation with allies.

During reviews like this in the UK, there is a history of limited consultation with NGOs and think tanks. This time around, I wasn’t part of that, but those I know who were never mentioned this change in policy. There was no expectation of it at all. The first that anyone heard about this specific proposal was a leak in the media a week before the Integrated Review was released. I believe this was a political leak. It was extensive. Draft copies of the report were actually shared with certain groups and some found their way into the hands of journalists. In trying to guess the reason for raising the cap, there was speculation that this was being done to encourage the U.S. Congress to fund the work on the W93 warhead, which in turn would defray the costs of the UK’s new warhead. To me, this doesn’t make very much sense, especially because a new warhead is a continuing issue of controversy in the U.S. and not certain to be funded at all.

The UK government also appeared to expand the number and type of future potential threats that could be met with the possibility of a nuclear response. Do you believe this was a good idea?

It’s a bad idea for a number of reasons. We have spent decades building a reputation among nuclear weapon states as the most forward-leaning on reducing the number of nuclear weapons and advancing the disarmament element of Article VI of the NPT (Treaty on the Nonproliferation of Nuclear Weapons). We were overtly minimalist and transparent about our nuclear arsenal. When I was Secretary of State for Defense, transparency was important both to explain that we had a minimum deterrent and that the fact that it was the minimum was credible. We’ve been clear for decades that we have a nuclear arsenal to deter nuclear-armed adversaries and prevent nuclear blackmail. We never said explicitly that it was its “sole purpose,” rather we made clear that the threat we were deterring had to be existential.

We’ve lost all of that goodwill now with this decision. Now, explicitly we’ve expanded the potential use of nuclear weapons to include deterring cyber and other ambiguous threats, including those generated by new technology. Now we’re embroiled in a debate about what is proportional and what isn’t. Also, we’re now in a space where we have to deny that nuclear weapons are for war fighting, but even supporters of the deterrent are uneasy about this change and are not convinced. We are engaging the possibility of first use of nuclear weapons. We’re suggesting we could start a nuclear war in an extreme circumstance. That’s so different from where we want to be as a country, ally, and partner.

There are no upsides to this. Only downsides.

Supporters of these decisions argue the international security environment has changed dramatically since you were the Secretary of State for Defense, necessitating this change. What is your response to that?

Since my time in the MoD (Ministry of Defense), we have been conscious of a changing international security environment. As the Review itself made clear, that dramatic change is more about what is called conduct in the gray zone. It’s about the willingness of our adversaries to conduct themselves in that gray zone in an aggressive or disruptive way that is not quite a declaration of war but is interfering in other countries’ decision-making. For example, the Chinese are said to have released a barrage of cyber-attack capabilities against Taiwan. So that has changed, that is significant. What has also changed is that large conventional platforms, even if they are mobile, like tanks, are no longer certain to give an advantage. Relatively cheap and small platforms, like drones, can defeat them now. So, they’re right about that. Things have changed.

I don’t buy the argument that this generates a role for nuclear weapons. To do so confuses the decision-making of those who have nuclear weapons and generates drivers of miscalculation. We increase opportunities for the chance of miscalculation and nuclear conflict. These changes belong in the conventional sphere and we need to work out a way to resolve these issues in the conventional sphere and to keep nuclear weapons out of this. We’re just creating problems and we’re not making it easier. Honestly, I’m surprised by this argument.

One thing we haven't discussed is the UK's simultaneous decision to stop publishing the details of its nuclear stockpile and missile numbers. Do you believe this was a wise decision?

We have had a longstanding commitment to transparency about the UK’s nuclear arsenal and support for agreements that require transparency, like New START (New Strategic Arms Reduction Treaty). From that position, among other nuclear weapon states, we had influence to encourage more transparency. If others see that we are not sticking to what we have publicly said and practiced in the past, it’s hard to get support for transparency from others. There is really no good explanation for ending this transparency. To explain it, they mix it up with the concept of “ambiguity” – which is supposed to be being ambiguous about when nuclear weapons would be used, not ambiguity about the numbers in the arsenal itself.

What is the likelihood that some or all of these decisions could be reversed by the current or a future UK government?

I’m not sure, but we’re already seeing a change in the rhetoric by official spokespersons about these decisions. If what is being reported is accurate, already they are rowing back, including admissions that, at least, they regret the communication of their decision. Not necessarily that they regret the decision, but still. I’ve been in politics a long time. Most policies that don’t communicate well are often bad policies. It’s seldom the message or messenger, usually it’s the policy.

Now, there’s a lot of “just because we can do this, doesn’t mean we are going to do this.” There’s a lot of focus on the cap being a cap and not an absolute number. They’re saying please don’t misunderstand us: we’re hedging against an uncertain and changing future and have to be ready for it. That’s different than what the Integrated Review itself actually says and we already had a hedge, more nuclear warheads to upload if necessary, we didn’t need more.

Their messaging is important. Official statements about the Integrated Review often ignore the nuclear component. It’s almost like they’re hoping people will just forget about it. When they are asked about it, they make political points and not policy points. That is another indication that they are unable to justify it. However, the damage has already been done.

Do you think the UK government was surprised by the negative international reaction to this aspect of the review?

Probably. But I am certainly not surprised.

Lord Browne of Ladyton (Des Browne) served as UK Secretary of State for Defense from 2006-2008 and was a Member of Parliament from 1997-2010. He is vice chairman of NTI.

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