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Michael Rühle[1] is Head, Hybrid Challenges and Energy Security, in NATO’s Emerging Security Challenges Division.  This is an adapted version of remarks he delivered at a National Institute for Public Policy symposium on June 21, 2021, addressing the implications of a U.S. “No First Use” nuclear policy.

The views expressed are the author’s own.


As the security environment changes, so does the value of certain policies and concepts. What may have looked like a bad idea in the past may look much better once circumstances change and a re-evaluation occurs. However, some bad ideas remain bad ideas, irrespective of changing circumstances. This is because despite their intellectual consistency, they tend to create more problems than they claim to solve.

Two classic examples of such policy ideas are the proposals for adopting a “No First Use” policy (NFU) and a “Sole Purpose” declaration (SP).[2] Despite exerting a certain fascination on some defense intellectuals, both ideas made little sense in the past, and they continue to make little sense today. This is not to deny that some of the circumstances that once made them look reckless, such as the Soviet Union’s massive conventional superiority in the Cold War, have disappeared. However, the implicit assumption of its proponents, namely that today’s environment is more conducive for such policy changes, remains fundamentally flawed.

While a changing security environment does indeed require the persistent adjustment of strategies and force postures, these adaptations must support a country’s most urgent political and security priorities. Preventing an attack on the U.S. or its allies is such a top priority, as is alliance management through extended deterrence. Alas, neither NFU nor SP would sensibly contribute to these goals. On the contrary, they would needlessly complicate them. Indeed, many of the alleged positive effects ascribed to NFU and/or SP, such as reducing the salience of nuclear weapons or avoiding nuclear escalation, only occur in the abstract world of academia. However, once applied to the real-life context of the U.S. and its allies coping with an increasingly competitive strategic environment, these ideas become outright counterproductive.

Nuclear Weapons and Extended Deterrence

Historically, the role of nuclear weapons in NATO has been gradually reduced, in line with U.S. nuclear policy. In the late 1950s, NATO’s defense plans foresaw the early employment of a large number of tactical nuclear weapons; in the 1990 London Summit Declaration, nuclear weapons had become “weapons of last resort”.[3] The number of European-based nuclear weapons went down from 7,000 in the late 1960s to a few hundred today. All these changes were a reflection of a changing strategic environment, which reduced the salience of nuclear weapons.

However, while NATO’s nuclear posture changed significantly, the core principles underlying NATO’s nuclear policy did not. After the end of the Cold War, nuclear sharing arrangements remained in place, various (half-hearted) national NFU initiatives were quickly dismissed, as were proposals to withdraw all U.S. nuclear weapons from NATO-Europe. More recently, Allies strongly rejected the Nuclear Ban Treaty. In short, even while their nuclear posture was changing, Allies avoided anything that could be interpreted as challenging the principles of extended nuclear deterrence.

The fact that NATO, even with far fewer nuclear weapons, considers itself a “nuclear Alliance” is hardly surprising. Nuclear weapons may not be as central to the defense of the Allies as they were in the Cold War, yet their deterrent effect remains crucial.[4] Together with U.S. conventional forces stationed in Europe, nuclear weapons are the ultimate expression of NATO as a defense community in which even nuclear risks and burdens are being shared between nuclear and non-nuclear Allies. This is as close as sovereign nation states can get to handling nuclear matters collectively. The well-known credibility dilemmas of extended nuclear deterrence pale in comparison to the benefits of the deterrence message this policy sends: the defense of allies is a vital U.S. interest. As Lawrence Freedman observed, nuclear weapons “can have a deterrent effect well beyond their logical limits”.[5]

Hence, any proposition to alter this policy – even if it were meant to be largely declaratory – would have to convince allies that their security would not suffer. Alas, many allies suspect that NFU and SP would ultimately result in a net loss of security, as it would symbolize a reduced U.S. commitment to European deterrence and defense.

Alliance Implications of No First Use and Sole Purpose

It is important to note that rejecting an NFU pledge does not equal a “first use” doctrine. Rather, by not ruling out the possibility of using nuclear weapons first, the defender seeks to keep the aggressor guessing about the response he has to expect. By contrast, a NFU commitment implies that the defender would rather lose a conventional war than employ nuclear weapons. If the aggressor stays below the nuclear threshold, so will the defender. Thus, in the Cold War, when the Soviet Union and its allies outgunned NATO conventionally, NFU was seen as counterproductive and thus had little political traction. However, even today, No First Use and Sole Purpose remain problematic:

First, due to the trappings of geography, Russia still enjoys a military advantage, for example against the Baltic States or in the Black Sea. The U.S. and its allies thus continue to benefit from the deterrence effect of potential nuclear escalation – arguably the most powerful reason for why the nuclear age has not seen major wars between nuclear powers or their closest allies. An NFU or SP pledge would diminish this deterrent effect and encourage Russia to believe that it could regionalize and dominate a conventional conflict.[6]

Second, both NFU and SP appear out of touch with the nuclear emphasis in Russia’s military doctrine. Russia’s quasi-religious attachment to its nuclear status, its comprehensive nuclear modernization, as well as its exercise patterns, do not suggest that Moscow would harbor particular inhibitions from using nuclear weapons whenever it deems it necessary for securing its victory or survival in a war. This does not suggest that Russia is relentlessly aggressive or reckless; yet it should caution against any Western move to politically and military constrain oneself on nuclear matters. At least many observers in Central and Eastern Europe will interpret such nuclear self-restraint as another sign of the U.S. trying to get out of a nuclear commitment that it finds too burdensome to maintain or to trade genuine security for the uncertain outcome and impact of arms control limitations.

Third, an NFU and/or SP pledge will lead to increased debate on possible structural changes in Western nuclear arsenals that will further diminish their deterrent value. A further reduced role for nuclear weapons would embolden those who argue that NATO Allies require fewer and less flexible nuclear capabilities. From a NATO perspective, this could lead to renewed questions from publics and parliaments about the requirement of the U.S. to forward deploy weapons in Europe and for NATO Allies to support the mission. An NFU or a SP pledge would also be at loggerheads with French and British nuclear policy, and it could re-ignite a discussion on the wisdom of the Nuclear Ban Treaty – a Treaty that NATO allies have categorically rejected.

Fourth, while there is currently no intense discussion in Europe about other WMD, the use of chemical weapons in Syria and the use of a highly toxic nerve agent by Russian assassins have brought these weapons back into the limelight. Even more importantly, the Corona pandemic – the origins of which are still debated – should serve as a strong reminder of the tremendous damage that non-nuclear WMD can inflict. Taking nuclear deterrence out of this equation would appear counterproductive, as it would simply increase the attractiveness of other WMD for certain malign actors. Put differently: if the U.S. Administration felt in 2010 that a “sole purpose” declaration was ill-advised with respect to biological weapons, a U.S. Administration today, which is still struggling with the fallout of the pandemic as well as with the implications of Emerging Disruptive Technologies, should be even more wary of such acts of self-constraint.[7]

Fifth and finally, the political and military gains claimed by the supporters of NFU/SP do not appear significant enough to become mainstays of U.S. security policy. In theory, reducing the salience of nuclear weapons in order to encourage progress in arms control or non-proliferation is logically sound. However, the current international environment is far more volatile than the period in which the Obama Administration’s Prague Agenda sought to achieve similar goals – and failed. The assumption that U.S. policies of nuclear restraint would convince others – even adversaries – to reciprocate, is the grand delusion of large parts of the Western nonproliferation community. In the current security environment, maintaining credible extended deterrence will be a greater boon for U.S. security than irritating its own allies with highly questionable policy changes. The West’s adversaries will closely watch how the U.S. will navigate the narrow straits between nuclear deterrence and nuclear risk reduction.


[1].     The author is indebted to Jessica Cox, Joseph Dobbs and Diego Ruiz Palmer for comments and suggestions. However, the views expressed are solely his own and do not reflect the official policy of the North Atlantic Treaty Organization.

[2].     No First Use means not using nuclear weapons first, whereas Sole Purpose means that the only rationale for nuclear weapons is to deter the use of other nuclear weapons. According to one opinion, “… sole purpose is [a] statement about why the United States possesses nuclear weapons, without necessarily imposing constraints on their use.” (Ankit Panda and Vipin Narang, “Sole Purpose Is Not No First Use: Nuclear Weapons and Declaratory Policy,” in War on the Rocks, 22 February 2021, available at https://warontherocks.com/2021/02/sole-purpose-is-not-no-first-use-nuclear-weapons-and-declaratory-policy/). However, the generous amount of sophistry employed in the authors’ arguments indicate the difficulties of explaining such policy modifications to the broader public. Thankfully, the authors recommend that before pursuing such changes, Washington should consult its allies.

[3].    This new terminology was seen by some as risky, as it could have been read as too much of a downgrading of nuclear weapons and nuclear deterrence. Accordingly, British Prime Minister Thatcher explained that in order to keep “the full deterrent effect” the phrase “last resort” should be construed in the context of “the comprehensive concept phraseology” employed in the entire paragraph of the Summit Declaration. See Margaret Thatcher, Press Conference after London NATO Summit, 6 July 1990, available at http://www.margaretthatcher.org/document/108139. The author is indebted to David S. Yost for his research on this episode.

[4].    As the 2016 Warsaw Summit put it: “The fundamental purpose of NATO’s nuclear capability is to preserve peace, prevent coercion, and deter aggression. Nuclear weapons are unique. Any employment of nuclear weapons against NATO would fundamentally alter the nature of a conflict. The circumstances in which NATO might have to use nuclear weapons are extremely remote. If the fundamental security of any of its members were to be threatened however, NATO has the capabilities and resolve to impose costs on an adversary that would be unacceptable and far outweigh the benefits that an adversary could hope to achieve.”

[5].     Lawrence Freedman, “Disarmament and Other Nuclear Norms,” The Washington Quarterly, Vol. 36, No. 2, (Spring 2013), p. 102, available at https://csis-website-prod.s3.amazonaws.com/s3fs-public/legacy_files/files/publication/TWQ_13Spring_Freedman.pdf.

[6].    In Asia, the situation may be even less conducive to U.S. nuclear policy modifications. For example, with Seoul being in range of North Korean artillery, an NFU pledge or Sole Purpose declaration would seem utterly misplaced.

[7].   The UK’s 2021 Integrated Review expanded the caveat to its negative security assurances to include “emerging technologies that could have a [strategic] impact.” See Global Britain in a competitive age: The Integrated Review of Security, Defence, Development and Foreign Policy, March 2021, p. 77, available at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/975077/Global_Britain_in_a_Competitive_Age-_the_Integrated_Review_of_Security__Defence__Development_and_Foreign_Policy.pdf. The 2018 U.S. Nuclear Posture Review listed “significant non-nuclear strategic attacks” as a potential trigger for nuclear use. See Department of Defense, Nuclear Posture Review, February 2018, p. 21, available at https://media.defense.gov/2018/Feb/02/2001872886/-1/-1/1/2018-NUCLEAR-POSTURE-REVIEW-FINAL-REPORT.PDF.

The National Institute for Public Policy’s Information Series is a periodic publication focusing on contemporary strategic issues affecting U.S. foreign and defense policy. It is a forum for promoting critical thinking on the evolving international security environment and how the dynamic geostrategic landscape affects U.S. national security. Contributors are recognized experts in the field of national security.

The views in this Information Series are those of the author and should not be construed as official U.S. Government policy, the official policy of the National Institute for Public Policy or any of its sponsors. For additional information about this publication or other publications by the National Institute Press, contact: Editor, National Institute Press, 9302 Lee Highway, Suite 750 |Fairfax, VA 22031 | (703) 293- 9181 |www.nipp.org. For access to previous issues of the National Institute Press Information Series, please visit http://www.nipp.org/national-institutepress/information-series/.

© National Institute Press, 2021

This article appeared originally at National Institute for Public Policy.

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