What Would Our Friends Think?

Views from Allies on the Future of U.S. Nuclear Armed Cruise Missiles

The Growing Debate

At the February 2016 Munich Security Conference, North Atlantic Treaty Organization (NATO) Secretary General Jens Stoltenberg spoke to gathered global leaders of seeking both defense against and dialogue with Russia, and emphasized NATO’s goals of avoiding confrontation or a new Cold War. His remarks on nuclear weapons generated media attention for their clarity in delivery:

“For NATO, the circumstances in which any use of nuclear weapons might have to be contemplated are extremely remote. But no one should think that nuclear weapons can be used as part of a conventional conflict. It would change the nature of any conflict fundamentally. NATO has continued to reduce the number of our nuclear weapons. We keep them safe, secure and effective. For deterrence and to preserve the peace. Not for coercion or intimidation.”(1)

These comments were carefully calibrated for multiple audiences and purposes — to send clear signals to Russia, to show the transparency in nuclear intentions demanded by non-nuclear weapon states, and to showcase the NATO resolution that is necessary for ensuring confidence across members of the alliance. But his speech also added insight to a perennial question on the minds of U.S. deterrence and arms control experts: how might allies and adversaries react to future alterations to U.S. nuclear weapons capabilities? Changes to the U.S. nuclear weapons arsenal warrant deep consideration about how each move could be viewed by allies such as NATO members, potential adversaries, and countries with which the United States must manage complicated relationships that mix elements of cooperation and competition.

In a pivot from the most prevalent U.S. nuclear debates since the New START treaty entered into force in 2011 — which in past years more commonly focused on numbers of intercontinental ballistic missiles and the costs of replacing the aging fleet of nuclear-capable submarines — nuclear armed cruise missiles emerged in the fall of 2015 to steal center stage. The U.S. debate has grown robust surrounding decisions to continue or cease long-term investments in a follow-on to the Cold War-era nuclear air-launched cruise missile (ALCM), which needs to be replaced or retired from the U.S. arsenal over the next 15 years. One former defense secretary, high ranking military and civilian defense officials, former ambassadors, media commentators, and a number of nuclear experts have deemed the ALCM’s planned replacement (the long-range standoff cruise missile, or LRSO) an important capability during the Cold War in which it originated, but a weapon that carries more risks than unique benefits in the current and most-likely future security environment.(2) Proponents of moving forward in building the LRSO have countered, often focusing on detailed scenarios in which a U.S. president may choose to use these weapons.

In late 2015, Vikram Singh and I argued for the need to broaden this debate to bring in international perspectives.(3) The views and concerns of our allies in particular should inform U.S. policy regarding the future of this type of nuclear weapon. In practice, international perceptions will matter as much as U.S. intentions in shaping whether this nuclear capability is stabilizing or destabilizing in the regions for which we aim to extend its deterrent effects.

Several common projections of ally reactions to U.S. nuclear weapons reductions have pervaded U.S. discourse for decades. One concern, put simply, is fear of a reduction of confidence in U.S. security assurances commensurate with reductions in nuclear weapons. Perhaps the most common is that our allies and others, having lost faith in the U.S. provision of security, will develop their own nuclear arsenals. This path is most commonly ascribed to South Korea and Japan, and is amplified at times when individual political leaders express a desire for their countries to go nuclear. Numerous books and articles have explored both the risks that could drive this leap and the myriad political, economic, historical, and security reasons the same countries continue to forego nuclear weapons.(4) Still, the concerns persist, often to the consternation of the treaty allies in question, in particular those with sound nonproliferation credentials.

Nuclear air-launched cruise missiles have remained outside of past arms control agreements like the New START treaty. As a result, robust international conversations regarding these weapons (and the future U.S. LRSO specifically) have yet to occur.

To begin the process of exploring potential reactions to U.S. decisions regarding the future of its nuclear armed cruise missile investments, I conducted personal interviews from 2015 to early 2016 with government officials, current and retired military leaders, and think tank and academic experts in Europe and East Asia. These interviewees included defense officials and diplomats, and ranged from the expert level to advisors to cabinet officials and heads of state. Their areas of focus ranged from deterrence and nuclear weapons policy (for officials interviewed from nuclear weapon states) to disarmament and arms control, to regional security and global strategy. While not a scientific or comprehensive survey,(5) these interviews provided several important messages and insights.

Views from Allies

The following messages were conveyed consistently across discussions in allied countries of Europe and Asia. They may serve as a starting point for continued efforts to bring wide-ranging international perspectives into the U.S. debate.

High confidence that the U.S. nuclear deterrent would remain strong with or without a new nuclear air-launched cruise missile.

Across both NATO countries and East Asian allies, government officials conveyed high confidence that the U.S. extended deterrent on which they rely will remain strong whether the air leg of the American triad has or omits nuclear armed cruise missiles in the future. No interviewee provided an exception to this sentiment, and indeed, several government officials reiterated this point multiple times. Moreover, officials from several countries conveyed confidence beyond just the weapons themselves, and stated clearly that they remain confident in the political will of U.S. leaders to take whatever actions our countries jointly agree are necessary across the full spectrum of conflict. This is worth reaffirming, even if it is not surprising.

If the Commander in Chief cancels investment in the LRSO, he or she would likely find significant international support.

All government officials and non-governmental experts interviewed were open to the idea of the U.S. president ceasing the replacement program for the air-launched cruise missile. Most openly welcomed it.

There were diverse and at times divergent reasons provided by interviewees for their support of a U.S. decision to forego the LRSO. Officials and experts in a few countries — including some who are vocal proponents of many U.S. nuclear weapon life extension programs — voiced concern that the LRSO is undeniably a new nuclear weapon and would be viewed as such by adversaries, thereby reducing U.S. credibility and risking unintentional provocation. In Europe and Asia, officials expressed serious concerns that the Obama administration has moved away from the path set by the 2010 Nuclear Posture Review (NPR) and the President’s 2009 Prague speech commitments, in particular the objective of setting conditions for making deterrence of nuclear attack on the United States or our allies and partners the sole purpose of U.S. nuclear weapons.(6) For these officials, a U.S. President cancelling the LRSO would show that U.S. leaders are acting in accordance with the tone and commitments established by the NPR, in particular if he or she stated clearly that investments in conventional extended-range capabilities meet the military requirements commonly associated with the ALCM and LRSO and thereby reduce the need for these particular nuclear weapons.(7)

Others expressed a strong desire for greater confidence that U.S. nuclear modernization plans are on a sound budget trajectory. Pentagon leaders have been open about the forthcoming challenges in funding its long-term plans, including nuclear modernization as currently scoped.(8) Though most officials of other governments avoid taking formal positions on U.S. internal defense budget tradeoffs, many expressed that halting investment in the LRSO would be a welcome signal that American officials are serious about ensuring an affordable long-term plan for maintaining a safe and strong nuclear deterrent.

Still others supported a U.S. decision to phase out nuclear armed cruise missiles due to their serious worry that an emerging emphasis on more “usable” nuclear weapons and “limited” nuclear exchanges — common arguments for the LRSO — may lower the perceived U.S. threshold of use or otherwise reduce the credibility of U.S. deterrence writ large. In Europe, several officials stated concerns that U.S. discussions of matching Russia’s investments and doctrine that emphasize using nuclear weapons for “de-escalation” and lower-yield retaliation inadvertently (and incorrectly) signals declining U.S. political will for massive retaliation in the most extreme Russian nuclear scenarios.

Comments by NATO Secretary General Stoltenberg to the Wall Street Journal after his Munich speech showed similar concerns. As he articulated, “No one should think it is possible to use nuclear weapons in a limited way as part of a conventional conflict,” and he noted the importance of countries not lowering the threshold for use of nuclear weapons.(9) A 2016 RAND report based on years of wargaming Russian security threats likewise concluded that approaches that rely on tactical and theater nuclear weapons suffer from similar credibility issues as scenarios of using strategic nuclear weapons.(10) One South Korean interviewee put simply his reaction to the argument that the LRSO is a necessary option for a limited nuclear strike against North Korea: in the warfighting scenarios in which experts posit a need for the U.S. President to have this option, “Seoul is already gone.”

The rationale most commonly provided for supporting a move by the United States to halt investments in a future nuclear-armed cruise missile did not stem from general anti-nuclear sentiments or from any sense of urgency in quickly reducing the numbers of nuclear weapons worldwide, as I had expected. Instead, most interviewees were enthusiastic about focusing on an eventual end to a type of nuclear weapon that few countries have as a practical, relatively low-cost option that can help reverse growing schisms between nuclear weapon and non-weapon states regarding next steps toward disarmament.

As is regularly emphasized in a variety of diplomatic arenas, frustration by non-nuclear weapon countries has grown over the past several years that weapon-possessing states are not actively-enough pursuing concrete next steps toward nuclear reductions. The United States and several key allies that depend on the U.S. nuclear umbrella currently sit on opposite sides of this divide.

The effects on the U.S.-Japan alliance are perhaps the most worrisome. Japan has submitted a relatively pragmatic resolution regarding disarmament to the United Nations every year since 1994, which the United States normally co-sponsors or supports. Due to a number of pressures and diplomatic dynamics, the United States, the United Kingdom, and France all abstained from Japan’s 2015 resolution, particularly striking to Japan given its submission during the 70th year after the Hiroshima and Nagasaki nuclear bombings. The country’s leaders and public have continued to take strong positions on new resolutions and other measures that focus on reducing the world’s nuclear weapons stockpiles, despite the opposition of the United States and other nuclear weapon states.(11)

Public narratives that the United States and those under its nuclear umbrella are diverging on nuclear weapons issues risk affecting the international perceptions that are critical to effective deterrence. A number of interviewees on both sides of the above-mentioned resolutions and debates, including in Japan and the United Kingdom(12), view U.S. and global discussions on phasing out nuclear armed cruise missiles as a viable step that can reunite these countries toward a common goal. While it is a medium- to long-term ambition, nearly every interviewee believed that a fully global end to these types of nuclear weapons should form the basis of a pragmatic dialogue among nuclear weapon and non-weapon states without delay.

Reassurance will be critical in the coming years — but it does not need to be nuclear.

Actions by North Korea, Russia, and others will keep contributing to security tensions for the foreseeable future. While a U.S. decision to cease investment in the LRSO would still leave the country with the current nuclear air-launched cruise missile for at least a decade, allies in Europe and Asia would seek for the United States to couple any move regarding the LRSO with clear, public reassurance. Notably, not a single interviewee suggested that this reassurance should take a nuclear form.

Instead, the United States could expect our allies to seek signals of support via conventional military assistance, training and exercises, and actions to strengthen political and economic ties — all coupled with well-orchestrated public diplomacy explaining that the U.S. decision is one of transparent long-term planning and prioritization, not a reduction in today’s capabilities. European partners specifically recommended bilateral (official and non-governmental) outreach with Poland and the Baltic countries in order to carefully gauge what reassurances would be most important to them. The budget President Obama submitted to Congress in February 2016 offered exactly the types of support in which NATO-country officials expressed the most interest, as it more than quadrupled the assistance provided through the European Reassurance Initiative to increase presence and prepositioning, conduct exercises, and otherwise support NATO partners in Europe.(13)

Allies in East Asia seek continual assurance of U.S. security commitments unique to each country’s history, basing arrangements, political trends, and other factors. As of this writing, missile defense arrangements, coordination regarding sanctions and other punitive action against the North Korean regime, and other non-nuclear measures are more central to their thinking than any long-term changes to the U.S. nuclear arsenal. The main departures from this lie in diplomatic channels, in which close allies such as Japan and Germany are seeking signs that the United States is not turning away from its commitment to continue reducing the roles and numbers of nuclear weapons over time. As the leadership of both nations face high anti-nuclear public opposition, any U.S. discussion of options that balance disarmament and deterrence needs would be welcome.

The Importance of China.

The 2010 U.S. Nuclear Posture Review is clear on its goal of maintaining strategic stability with both Russia and China. Unlike with Russia, the large gap in numbers of nuclear weapons possessed by the United States and China continues to preclude the traditional model of bilateral arms control and disarmament discussions. Yet officials in Tokyo, Seoul, and several European capitals expressed great hope that nuclear armed cruise missiles could offer a productive means of U.S.-China engagement on strategic stability — even if this engagement begins at a Track II level and takes time to progress. One reason is the prospect for China to be viewed as a leader and responsible nuclear weapon state by agreeing to a global commitment against nuclear armed cruise missiles. China does not currently possess them. Its leaders would need only to forego developing these specific types of nuclear weapons, though the political decision to do so will be quite complex given its past and current relations with the United States and its nuclear and non-nuclear neighbors.

There is potential for China to take such a decision unilaterally, or in cooperation with the United Kingdom or others. For considering the potential for a U.S.-China conversation, James Steinberg and Michael O’Hanlon offered a useful framework in their 2014 book, Strategic Reassurance and Resolve: U.S.-China Relations in the Twenty-First Century. As they wrote, “Nowhere are the dangers of U.S.-China security competition more acute or the opportunities so great for managing them than in the area of so-called strategic systems — nuclear weapons, national missile defense, and high-level command and control capabilities including space and cyber assets.” Their book modernizes the concept of strategic reassurance beyond the term’s Cold War-era nuclear definitions in ways that are useful in considering how U.S. nuclear decisions may affect already-complex relations with China:

“At its core, the goal of strategic reassurance is twofold: first to give credibility to each side’s profession of good intentions by reducing as much as possible the ambiguity and uncertainty associated with unilateral security policies; and second, to provide timely indicators and warnings of any less benign intentions to allow each side adequate time to adjust its own policies to reflect a new reality.”(14)

The authors’ point on reducing ambiguity would resonate with deterrence officials in several countries who voiced concern that recipient countries’ inability to differentiate between nuclear and conventional cruise missiles introduces unnecessary and dangerous risk of miscalculation. Although they don’t mention the ALCM or LSRO specifically, the authors highlight China’s possible perception that U.S. long-range strike investments will reduce their nuclear command and control capabilities. Without strategic reassurance regarding such capabilities, they write, “China’s likely response will be to accelerate not only its offensive nuclear capability but also its development of its own missile defenses and other asymmetric counters,” with follow-on effects that increase instability and the risk of conflict.(15) On the other hand, the transparency demonstrated by discussions between China and the United States regarding any nuclear investments could build trust and reduce risk in various aspects of the bilateral relationship.

Speaking to officials and experts in China is the only real way to determine what pathways exist (or do not) for U.S.-China or multilateral discussions of a future without nuclear armed cruise missiles.

Deep interest in further international dialogue.

Although no interviewees voiced opposition to the concept of the United States foregoing plans to replace its nuclear armed cruise missiles, many raised important questions they would like to work through via both government and non-governmental channels, beginning as early as 2016. The most common questions centered on timing — both how to use the remaining lifespan of the ALCM to shape the security environment and how to time an announcement if the US were to alter the investment trajectory for the LRSO. International dialogues that show broad support for a global end to these weapons could reduce the complexity of timing the announcement of decisions by any single country.

Requests for further dialogue took different angles for interviewees in different countries. Not surprisingly, European officials showed keen interest in coupling discussions of future nuclear reductions with discussions of non-nuclear (and non-military) reassurance. Such dialogues could include how to broadcast that nuclear reductions are done from a position of strength and calculated to enhance stability, and how to message to their publics, in particular those countries most geographically proximate to Russian threats and where anti-nuclear sentiment puts great pressure on government offices.

There was great desire among NATO and East Asian respondents for future official deterrence and disarmament dialogues to include broader representation of non-nuclear experts. For NATO countries, there was strong sentiment that it was important to include officials who are attuned to how alliance decisions and actions play into domestic political considerations, and others who are charged with navigating intra-NATO political dynamics. Gordon Adams and Richard Sokolsky recently proposed a similar approach for the United States and Russia in Foreign Affairs, writing that the countries “can and should begin a new high-level dialogue on deterrence and security issues writ large, including on the impact of planned developments in strategic and tactical nuclear weapons, conventional forces, cyberweapons, and missile defenses.”(16) In South Korea, including experts on domestic sentiments and public diplomacy would be particularly useful; defense decisions involving the United States are too-often seen as being announced with insufficient explanation of rationale to the public, which can reduce political support.

Officials and experts in Japan likewise expressed interest in either quiet bilateral or more open multilateral discussions on the future of nuclear armed cruise missiles. Their views were informed by experiences with U.S. announcements putting into storage its nuclear sea-launched cruise missile, or TLAM-N, program. As that weapon was viewed as uniquely useful to extended deterrence in East Asia, many reacted negatively when its discontinuation was announced without better planning between Washington and Tokyo. Japan’s reinvigorated interest in next steps on the disarmament path, the U.S. air-launched cruise missile not holding a role as unique to their security calculations as the TLAM-N was, and deep interest in stability with regard to North Korea and China all contributed to many interviewees in Tokyo welcoming further discussions.


No changes to U.S. nuclear weapons plans come without risk. Any dialogue on our nuclear future must include measures to ensure conventional capabilities remain sufficiently robust to handle the known and unknown dynamics of the future security environment, bearing in mind that conventional replacements to nuclear weapons can also be provocative if not managed carefully. The United States also risks the international community viewing a cruise missile focus as too easy and their discontinuation a means of avoiding greater reductions in intercontinental ballistic missiles and other nuclear assets.

Yet it is clear that multilateral dialogues to develop potential future pathways for nuclear-armed cruise missiles would be fruitful. It is likewise clear that any U.S. decision must be taken in a global context. Security needs will continue to shift, and there are simple ways to reduce the risks of international misperceptions regarding these weapons. Indeed, discussing the global future of nuclear cruise missiles may be more fruitful and more stabilizing than a narrower focus on just U.S. weapons. Both official and non-governmental channels should be activated to bring important insights into the mix, and lessons from non-governmental discussions should be made publicly available at least in basic form. For decisions as dynamic and important as altering investments in the nuclear armed cruise missiles, looking to our friends and beyond to foster a rich international debate is a prudent next step.


1. NATO Secretary General Jens Stoltenberg, Remarks at the Munich Security Conference, February 13, 2016, http://www.nato.int/cps/en/natohq/opinions_128047.htm.

2. Arguments against replacing the ALCM include the potential for destabilizing misunderstandings regarding their intended uses, the robustness of other air-based nuclear capabilities, and redundancies with more usable non-nuclear extended range weapons, among other concerns. See, for example: William Perry and Andrew Weber, “Mr. President, Kill the New Cruise Missile,” The Washington Post, October 15, 2015; Editorial Board, “A Nuclear Weapon the U.S. Doesn’t Need,” Bloomberg News, February 1, 2016; Lt. Gen. Robert Gard and Sarah Tully, “Nuke Plans for a New Nuclear Cruise Missile,” US News & World Report, November 27, 2015; Stephen Young, US Is More Secure Without New, Nuclear-armed Cruise Missile,” Defense News, January 13, 2016.

3. Christine Parthemore and Vikram Singh, “Time to Internationalize the Dialogue on Nuclear Armed Cruise Missiles,” War on the Rocks, December 15, 2015.

4. Among countless examples are Kurt Campbell, Mitchell Reiss, and Robert Einhorn, eds., The Nuclear Tipping Point: Why States Reconsider Their Nuclear Choices (Washington, DC: Brookings Institution Press, 2004); and Jacques E.C. Hymans, “Veto Players, Nuclear Energy, and Nonproliferation: Domestic Institutional Barriers to a Japanese Bomb,” International Security, volume 36, issue 2, pages 154–189, Fall 2011.

5. For example, I chose not to interview non-governmental advocates whose current work focuses on the humanitarian consequences of nuclear weapons use or who advocate for swift elimination of all nuclear weapons, though these voices are important in shaping the U.S. and international nuclear dialogues. All interviews were conducted on a not-for-attribution basis, though many interviewees have publicly expressed the perspectives compiled for this article.

6. U.S. Department of Defense, “Nuclear Posture Review,” 2010, page ix.

7. Hans Kristensen, “Forget LRSO; JASSM-ER Can Do The Job,” Federation of American Scientists, December 16, 2015.

8. Aaron Mehta,Is the Pentagon’s Budget About To Be Nuked? The Pentagon is ready to begin sweeping nuclear modernization. Can it afford to do it? Can it afford not to?” Defense News, February 2016.

9. Julian E. Barnes, “NATO Accuses Russia of Loose Talk on Nuclear Weapons: Officials say threats blur lines on warfare; Moscow accuses U.S. of undermining deterrence,” The Wall Street Journal, February 13, 2016.

10. David A. Shlapak and Michael Johnson, Reinforcing Deterrence on NATO’s Eastern Flank: Wargaming the Defense of the Baltics, (Santa Monica, CA: RAND Corporation, 2016), http://www.rand.org/pubs/research_reports/RR1253.html.

11. “Japan loses support of U.S., Britain, France for U.N. resolution on abolishing nukes,” The Asahi Shimbun, November 4, 2015; “Editorial: Japan should lead U.N. talks to establish nuclear ban treaty,” The Asahi Shimbun, February 5, 2016.

12. The United Kingdom has already taken the decision to maintain a nuclear deterrent solely of ballistic missiles. In a 2013 op-ed, Defense Secretary Philip Hammond wrote that for the United Kingdom, “the cruise option would carry enormous financial, technical and strategic risk.” Philip Hammond, “The alternatives to Trident carry an enormous risk,” The Telegraph, February 2, 2013.

13. The White House, “Fact Sheet: The FY2017 European Reassurance Initiative Budget Request,” February 2, 2016.

14. James Steinberg and Michael O’Hanlon, Strategic Reassurance and Resolve: U.S.-China Relations in the Twenty-First Century, (Princeton, NJ: Princeton University Press, 2014), pages 5–6.

15. Ibid., pages 158–9.

16. Richard Sokolsky and Gordon Adams, “The Problem With NATO’s Nukes: Time to Rid Europe of Its Cold War Legacy,” Foreign Affairs, February 9, 2016, https://www.foreignaffairs.com/articles/russian-federation/2016-02-09/problem-natos-nukes

About the Author: Christine Parthemore is a Council on Foreign Relations International Affairs Fellow in Japan. She served as the Senior Advisor to the Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs in the U.S. Department of Defense from 2011 to 2015. She is the founder of CLP Global, LLC and an adjunct professor in the Global Security Studies Program at Johns Hopkins University, and has worked at several think tanks in Washington. The views expressed in this article are those of the authors and do not represent the official policy or position of the Department of Defense or U.S. Government.