Britain Leads the Way to Global Zero

Harold Smith and Raymond Jeanloz

The United Kingdom, not the United States or Russia, is leading the way along a path to a possible world without nuclear weapons. The British not only are reducing the number of nuclear weapons, but in so doing are making an implicit statement, through the resultant force posture, about the kind of deterrence that nuclear weapons provide. Can and should the superpowers follow the same path?

In October, Prime Minister David Cameron presented to Parliament the government’s “Strategic Defence and Security Review” (SDSR)[1] which stated explicitly that the number of nuclear weapons in the British arsenal would be reduced to 180, of which 120 would be operational. Furthermore, the United Kingdom will maintain only one type of weapon, and that weapon can be launched only by ballistic missiles carried aboard four Vanguard-class nuclear submarines.[2] As such, a majority of those weapons may be considered invulnerable. Further, they can be launched at the discretion of the leadership at any time against any target of choice. They are not “use or lose.” They need not be on high alert. It all sounds like progress toward a world with far fewer, if not zero, nuclear weapons.

Such nuclear restraint did not occur in the United Kingdom without significant debate within the Labour government, within the newly elected Conservative-Liberal Democrat coalition, and in the public arena. One suspects that such a debate would be even more forceful in the United States and in Russia, at least within the Kremlin, if the two superpowers chose to follow the British lead.

The decision to base its nuclear deterrent solely on new Vanguard submarines was first announced by the Labour government in December 2006 and modified by the present government with the publication of the SDSR, which is unlikely to change the deployment scheme, notwithstanding the search for “alternatives,” i.e., cruise missiles, by the Liberal Democrats. So far, the British are sticking to their guns, although there will be fewer guns.

The declaratory policy that accompanies the announced deployment states that the United Kingdom will be prepared to maintain its nuclear deterrent into the indefinite future, but remains committed to a world without nuclear weapons. Furthermore, the document says that the United Kingdom will not use its nuclear weapons against those parties to the nuclear Nonproliferation Treaty that continue to forswear nuclear weapons. The United Kingdom promises to contribute to deterrence by NATO, although this will be from afar; the British withdrew their tactical nuclear weapons during the Clinton administration. The SDSR describes this policy as “deliberately ambiguous about precisely when, how, and at what scale we would contemplate their use.”[3] Nevertheless, the size of the “scale” clearly has changed, and with that change comes a reduction in ambiguity, which in turn offers some insight into a world with far fewer nuclear weapons.

Nuclear Doctrine With Small Arsenals

At such low numbers, the British arsenal, no matter how accurate the weapons may be, cannot necessarily be counted on to destroy the military capability of all nuclear powers that might threaten the United Kingdom. The technology and operational skill required to harden silos and command centers or move these military targets in unpredictable ways or place nuclear-armed aircraft on dispersed bases or even on airborne alert are well known and can be implemented at reasonable expense and, in some cases, on short notice. The five established nuclear-weapon states have already done so, and the rising nuclear powers can proceed to do so at whatever pace they feel the situation requires. Furthermore, if ballistic missile defense can be successfully developed and deployed to protect military targets, even more retaliatory capability would survive an attack from an arsenal as small as the one described in the SDSR. Even a pre-emptive first strike by the United Kingdom from such an arsenal against an enemy, protected as noted, would leave enough surviving enemy capability to destroy tens of British population centers in retaliation. In short, it would be folly for the United Kingdom to launch a pre-emptive attack against military targets, and it would be impossible to do so in a retaliatory mode.

One presumes, therefore, that the British have forsaken military targets and will achieve deterrence by threatening, explicitly or implicitly, to destroy the enemy’s cities, industrial centers, and communications. In the parlance of the Cold War, the British arsenal is countervalue, not counterforce.[4] It is nuclear deterrence in its starkest form; there is no sense of a presumed victory by virtue of quickly destroying an enemy’s nuclear arsenal before that opponent can strike back.

It would appear that all the nuclear powers will have to follow the United Kingdom if or as they move toward a world without nuclear weapons. Small, invulnerable, non-time-sensitive arsenals deployed far from areas of contention and with a high degree of transparency under a countervalue strategy are probably as safe as a world with significantly fewer remaining nuclear weapons can be, and they certainly seem safer than a world with thousands of nuclear weapons ready to be launched on a moment’s notice against military targets. The shift from military to civilian targeting, which seems barbaric, thus may be a feature of the path to “global zero” along with the phased, verified elimination of nuclear weapons.[5]

None of these conclusions would change if the United Kingdom decided to deploy its warheads on cruise missiles, as advocated by the Liberal Democrats. Admittedly, funding could be reduced, but the security of the warheads would be less; targeting flexibility would be compromised by the reduced range of the cruise missiles; vulnerability to in-flight destruction would increase; and transparency of deployment would be less. Nonetheless, fiscal realities can become paramount, and the deployment scheme might change. However, the need to threaten cities will remain as long as the arsenal remains small, which is a necessary part of fiscal reality in the first place.

Obstacles Along the Path

What seems straightforward for the United Kingdom is far more challenging for Russia and the United States. First of all, both countries have enormous arsenals fully capable of destroying vast numbers of military targets. It will not be easy for the large nuclear bureaucracies of the two superpowers that have decades of counterforce planning and targeting to shift easily to a countervalue strategy. Witness the recent U.S. Nuclear Posture Review, which lauds reduced arsenals but keeps the missiles on high alert.[6]

Tactical nuclear weapons, which the British have forsworn, are designed for use against military targets on the battlefield and remain a problem for the superpowers. During the Cold War, NATO deployed U.S. and British nuclear weapons along the East-West German border to stop a feared advance by the Red Army. Those days are gone, but the belief and the American weapons remain,[7] although under increasing debate, particularly within those NATO countries where the weapons are based.[8] Possibly within a few years, U.S. tactical nuclear weapons will no longer be a roadblock along the path that the British have delineated.

With or without the presence in Europe of these U.S. weapons, it will be far more difficult for Russia to follow the British lead and eliminate its own tactical nuclear weapons. To its south, Russia sees a resurgent China armed by the large and powerful People’s Liberation Army at the same time that the Red Army is a shadow of its former self.

The superpowers are not necessarily alone, however, in their reluctance to eliminate such tactical weapons. Along the Indian-Pakistani border, each country fears invasion by the other and has presumably built a nuclear arsenal for tactical defense in the event of attack across the border and for strategic deterrence if the attack proves to be more than an incursion. The same could be said for North Korea. In the Middle East, Israel is threatened by attack from all quarters, and Iran is well aware of discussions of a military response to its nuclear program. All may decide that tactical weapons are a necessary part of their nuclear arsenals.

China and France, whose arsenals are somewhat larger than the United Kingdom’s but far less than those of the United States and Russia, may have rejected a counterforce doctrine already. Although it is easier for the United States to discuss nuclear strategy with France than with China, the variety of weapons and basing options for those weapons by both countries complicates any attempt to discern their ultimate doctrines. Presumably, both nations have some of their nuclear weapons deployed for quick attack or counterattack on military targets. Ambiguity, not the transparency demonstrated by the British, is the guiding characteristic.

Can the United States follow the British lead? Technically, it may have no choice. Counterforce doctrine always may have been a fiction, implemented to soften the image of threatening to destroy millions of people by claiming that only military targets would be attacked. Demographic trends, however, suggest that the difference in carnage between the two doctrines becomes less with each advancing year. The past decades’ increases in world population and in urbanization imply that attacks on military facilities would likely result in massive casualties; the distinction between target and collateral damage are becoming more blurred than ever.

Furthermore, technology and economics have combined to make it easier to place key military targets beyond the reach of nuclear weapons. It is easier and cheaper to bury such targets ever deeper than it is to build the nuclear weapons that could destroy them. Only the cities remain truly vulnerable.

Finally, the most worrisome enemy of the United States is not any other country, whether it possesses nuclear weapons or not. It is the extranational terrorists, who claim that they will not hesitate to detonate on U.S. soil as many nuclear weapons as they can obtain.[9] Suicidal terrorists will not be deterred by nuclear weapons, whether strategic or tactical, or whether deployed in a counterforce or countervalue mode. They simply want the weapon, and the more of those that are deployed for military targeting on or near potential battlefields, as opposed to submarines, the better from the terrorist’s point of view. The British understand this, but whether the other nuclear powers do remains to be seen.

Major decisions such as the size and deployment of nuclear weapons are only partially influenced by military, technical, or bureaucratic considerations. There is always a political side. To oversimplify only slightly, a willingness by the United States to admit that it will destroy cities, as opposed to military targets such as missile silos in remote areas, would be met with horror on the left, where humanitarian virtues are extolled, and with disbelief on the right, where military capability is never to be forsworn. One can easily imagine the speeches, editorials, and blog posts that would follow an official announcement of such a shift in nuclear doctrine or even public awareness of an unannounced shift.

If such an announcement were deemed politically acceptable, as seems to be the case in the United Kingdom, negotiations between the United States and Russia on truly large reductions in their arsenals would challenge King Solomon. The Russians plausibly will insist that they retain their tactical nuclear weapons for purposes of defense, and the Americans just as plausibly will not agree to any reductions that violate reasonable parity with the Russians.

Compromise on these issues may not be easy, but the elimination of U.S. tactical weapons on the basis that the Russians have already removed theirs from Europe, although politically difficult, would be a major step in the direction of global zero. The Russians have long made it known that they resent the lack of reciprocity by the United States in removing nuclear weapons from European countries. It is perhaps unlikely that responding favorably to this criticism will lead to elimination of all superpower tactical nuclear weapons, but doing so could well set the stage for serious discussion of one of the major obstacles on the path to global zero.

Next Steps

If other countries are to follow the British lead, the next step must be a search by the superpowers for agreement to reduce their arsenals and to deploy them as the United Kingdom has proposed. If they can agree, the implementation of an agreement is not as difficult as might be supposed. There is already ample experience, even trust, between Russians and Americans on the inspection and mutual verification of submarine-based warheads. Submarines are large, few in number, and return periodically to known ports. Mutually acceptable inspection and verification should be feasible.

The difficulty will not be in verifying a prescribed, submarine-based arsenal, but rather in ensuring that there are no significant numbers of hidden weapons. However, this is exactly the problem that the world will have to face if and when the goals of global zero seem to be within reach. There is no better way to approach the problem of hidden and forbidden weapons in a world where, supposedly, there are none, than for the superpowers, while maintaining small, effective, and verifiable arsenals, to seek ways to convince themselves that there are no hidden weapons. If Russia and the United States can find a way to a bilateral agreement along these lines, a major step will have been taken on the path to global zero. Conversely, if the superpowers cannot ensure themselves that the opposing power has no hidden nuclear weapons, when a few hundred remain operational aboard submarines, there is little hope that they will agree to a world where they have no nuclear weapons at their disposal.

What works for the British, and for which they are to be commended, may not be acceptable to the other nuclear powers. George Shultz and his co-authors never said that the path to global zero would be either short or easy.[10] Although many initial and useful steps have been suggested and some have been implemented, there are difficult turns in the road ahead. One of them is the realization that the remaining weapons will be deployed not against remote military targets, but against those targets that the enemy holds most dear. It would not be a pretty world, but it could be a much better one.

Harold Smith, who was assistant to the secretary of defense for nuclear, chemical and biological defense programs in the Clinton administration, is a distinguished scholar in residence at the Institute for Governmental Studies at the University of California at Berkeley. He is chair of the Federation of American Scientists. Raymond Jeanloz is a professor of astronomy and earth and planetary science at the university. He chairs the National Academy of Sciences Committee on International Security and Arms Control.


1. “Securing Britain in an Age of Uncertainty: The Strategic Defence and Security Review,” Cm 7948, October 2010, (hereinafter “Strategic Defence and Security Review”).

2. The government intends to study the possibility of reducing the number of boats to three. A decision will be made in 2016. The first boat will not go to sea until 2028.

3. “Strategic Defence and Security Review,” p. 37.

4. For a brief description of counterforce versus countervalue, see

5. For a presentation of other and earlier milestones, see Sidney Drell, “Working Toward a World Without Nuclear Weapons,” Physics Today, July 2010.

6. U.S. Department of Defense, “Nuclear Posture Review Report,” April 2010.

7. The Strategic Defence and Security Review maintains that the United Kingdom will continue to meet its nuclear commitment to NATO by assigning warheads and missiles from its strategic arsenal, not from weapons located within Europe. “Strategic Defence and Security Review,” p. 37.

8. Oliver Meier, “NATO Struggles to Define New Nuclear Doctrine,” Arms Control Today, September 2010.

9. Matthew Bunn, “Securing the Bomb 2010: Securing All Nuclear Materials in Four Years,” April 2010, p. 13,

10. George P. Shultz, William J. Perry, Henry A. Kissinger, and Sam Nunn, “A World Free of Nuclear Weapons,” The Wall Street Journal, January 4, 2007, p. A15.