U.S. Nuclear Strategy

30 January 2018, U.S. President Trump, during his State of the Union speech, called for a nuclear arsenal “so strong and powerful that it will deter any acts of aggression.”

The President made clear that his first priority is to protect the United States, allies, and partners. The 2018 Nuclear Posture Review (2018 NPR) lays out important policy changes with regard to U.S. nuclear weapons. The renewal of its nuclear forces will have huge implications for the security of the country and its allies, its public finances and the salience of nuclear weapons in global politics. While the United States has continued to reduce the number and salience of nuclear weapons, others, including Russia and China, have moved in the opposite direction. They have added new types of nuclear capabilities to their arsenals, increased the salience of nuclear forces in their strategies and plans, and engaged in increasingly aggressive behavior, including in outer space and cyber space. Current plans provide for spending an estimated US$1,200 billion over 30 years to modernise or replace U.S. nuclear arsenal.

No consensus exists as to whether the use of nuclear weapons is in fact an option for decision makers to consider or whether the goal is to ensure that they can never be used. The different strategies that have been developed since 1945 for U.S. nuclear strategy—massive retaliation, flexible response, a fatalistic acceptance of the logic of mutually assured destruction, and the search for the most effective ways of stemming nuclear proliferation in unstable or unpredictable actors—all reflect attempts to provide guidance for policymakers as to the strategic purpose of these weapons.

Nuclear deterrence may have emerged with the Cold War, but that does not mean that just because the Cold War is over, nuclear weapons and deterrence are no longer relevant to U.S. grand strategy and security. The overall aim of the U.S. nuclear weapons arsenal (deterrence) has not changed and, as in the past, it is stated that nuclear weapons will only be used in the ‘most extreme circumstances’.

2010 NPR versus 2018 NPR

Under the Obama administration, the Pentagon had already planned in the 2010 Nuclear Posture Review (2010 NPR) to modernize the nation’s nuclear weaponry, which consists of missiles fired from land and sea and bombs from warplanes. The 2018 NPR reiterates the announcement made in the 2010 NPR that the U.S. ‘will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the Non-Proliferation Treaty (NPT) and in compliance with their nuclear non-proliferation obligations.’ However, there are two important differences between the 2010 and 2018 NPR:

1. 2010 NPR: nuclear weapons will be used to retaliate (and thus deter) nuclear attacks only. 2018 NPR: Nuclear weapons may be used in response to ‘significant non-nuclear

   strategic attacks’, including attacks on civilian population or infrastructure. Retaliation against massive cyber-attacks or against any actor that ‘supports or enables terrorist efforts to obtain or employ nuclear devices' may also involve the use of nuclear weapons. Trump’s NPR suggests that the role of nuclear weapons in U.S. security policy will not decrease, as in Obama’s NPR, but rather increase.

2. 2010 NPR: the U.S. will not develop new nuclear warheads. 2018 NPR plans for new types of warheads: low-yield warheads to be used by existing Sea-Launched Ballistic Missiles (SLBM) and/or a – newly to be developed – Sea-Launched Cruise Missile (SLCM). Lower-yield weapons, causing less (collateral) damage, ‘will help counter any mistaken perception of an exploitable

   “gap” in U.S. regional deterrence capabilities’, the 2018 NPR assumes.

   The current U.S. Administration apparently believes that nuclear war can be controlled: a U.S. response with low-yield weapons to Russian use of tactical nuclear weapons could prevent immediate escalation to the release of the strategic arsenal. Many critics actually doubt whether nuclear war can be controlled once both sides have started to use (tactical or low-yield) nuclear weapons.

Impact on NATO and Europe

The NATO Strategic Concept of 2010 underlines that the fundamental purpose of Alliance nuclear forces is deterrence. Allies also agreed in 2010 on “seeking to create the conditions and considering options for further reductions of non-strategic nuclear weapons assigned to NATO”. Any NPR has direct effects on the European member states of NATO –a nuclear alliance relying significantly on U.S. nuclear weapons. The 2018 NPR seems to consider the non-strategic component as the weakest element in the U.S. nuclear posture in view of the continued existence and modernisation of the Russian short- and medium-range nuclear weapons. The development of low-yield SLBMs and SLCMs is meant to fill this ‘nuclear gap’. As they are sea-based, European countries risk being out of the loop when it comes to formulating their role unless they become part of NATO’s nuclear force posture. Mentioning the option of developing a ground-based nuclear capability for the intermediate range is an option with far-reaching consequences. If Trump were to call on European Allies to share the nuclear burden by planning the deployment of nuclear ALCMs by their Dual Capable Aircraft in Belgium, Germany, Italy, the Netherlands and Turkey, it would also generate a huge political debate in the Alliance. Transatlantic security and defence relations may be negatively affected if Washington perceives a lack of will on the part of European NATO allies to support the U.S. in implementing the NPR. A political debate on the role of nuclear weapons might raise questions on the future role of the French and British nuclear forces in ‘Europeanising’ the nuclear arsenals. Taking into account Brexit and London’s dependency on the US for maintaining and modernising the Trident SLBMs, such a Europeanisation is less likely in the British case. As France is the only continental European country with an independent nuclear arsenal, which in general can be maintained and modernised without any outside involvement, Paris will hold the key to any form of Europeanising its nuclear forces (or part of it).

Conclusion

It would be difficult to envisage returning to non-nuclear capabilities as the primary instruments for deterring major war between great powers. Instead, US nuclear strategy will have to be continually updated to deal with new technologies, new threats, and new contexts, especially now "the United States faces a more diverse and advanced nuclear-threat environment than ever before, with considerable dynamism in potential adversaries’ development and deployment programs for nuclear weapons and delivery systems."

Nuclear deterrence can best be accompanied by a set of arms control agreements and crisis-control measures to prevent unintended nuclear war. However, the 2018 NPR does not reflect any ambition in this regard. The introduction of new types of ‘smaller’, low-yield nuclear weapons may contribute to lowering the threshold for nuclear weapons use and blur the difference between nuclear and conventional weapons. This in turn may endanger the global norm against nuclear weapons use and increase the risks of nuclear warfare because of misunderstandings and miscalculation. With the risk of a renewed nuclear arms race on the horizon, European allies should emphasise the need for serious arms control and risk reduction efforts between the US and other nuclear weapons states to prevent a dangerous spiral of continuously increasing nuclear escalation risks.