by Orion Noda
Deterrence theory is almost as old as the nuclear age. Consequently, the idea of Mutual Assured Destruction (MAD) and the use of nuclear weapons as a retaliatory deterrent has dominated the field of nuclear weapons and politics from the 1950s onwards. However, like any field, a series of biases infect it. This blind trust and belief in the postulations of Deterrence Theory has established what Nick Ritchie called the “regime of nuclear truth” and denominated “nuclear absolutism.” The effects of this unquestionable belief in Deterrence Theory sharply increases States’ reliance on and valuing of nuclear weapons. Consequentially, it poses an existential threat to disarmament processes and severely undermines nuclear weapon States’ Article VI obligations under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). It is long past time these ‘truths’ were punctured.
Deterrence Theory, derived from a Realist school of thought, postulates that the possession of nuclear weapons – the ultimate deterrent – will thwart and deter attacks against the possessor. The sheer destructive power inherent in a single nuclear weapon, let alone thousands detonating in quick succession, make their use (almost) unthinkable. As a means to solidifying a unified front against the Soviet Union in the aftermath of the Second World War, the Western European States along with the United States formed the North Atlantic Treaty Organization (NATO) in 1949 to deter the Soviet Union’s massive conventional forces, as well as its ever-increasing nuclear arsenal after its first test a few months later. With NATO, the United States became the guarantor of the defence of Western Europe, and the so-called US nuclear umbrella was born.
As stated in Article V of the NATO treaty, an attack on one member was an attack on all of them. The US nuclear umbrella is, therefore, a security assurance agreement that the US deterrent intended primarily to defend itself, also extends over the territory of its NATO partners. In other words, the United States would defend NATO members against aggressors, even resorting to nuclear weapons, should the situation require these capabilities to be deployed. In theory, the US nuclear umbrella would soothe NATO members’ anxieties and serve as an alternative to the acquisition of their own nuclear weapons. However, given its Realist roots, the crucial question arises: when push comes to shove, would the United States be willing to risk its own security to defend its allies in Europe? What are the costs of sustaining the illusion of the US nuclear umbrella? While these questions retained an academic quality for some time, in the Age of Trump, they urgently require revisiting.
Alliances under Anarchy: a Realist Take
Realism puts significant emphasis on self-help given the anarchical setting of the International System. Cooperation is scarce and limited, and only possible if states see it in their primal interest of survival and quest for power. Nevertheless, military alliances do happen and are circumscribed in the theoretical postulations of Realism—they last for as long as the states involved see it as comparatively advantageous. In particular, alliances are formed to counter a third, more powerful, state.
The US nuclear umbrella, one of the crown jewels of NATO, relies heavily on the existence and credibility of military alliances. If the alliance fails, so do the security assurances. In that sense, even though military alliances do exist, it seems almost incredible that, under Deterrence and, therefore, Realist logic, military alliances would include credible nuclear security assurances. In other words, following the Realist rationale of self-help and its ultimate goal of survival, it seems highly unlikely that a state would risk its own security and survival to come to the defence of another state, ally or not, that is threatened by a third.
Historically, military alliances based on mutual assistance and defence have proven to be nothing but empty promises. In 1924, Czechoslovakia and France signed the Treaty of Alliance and Friendship, which stated that the two States would come to the other’s aid in times of peril. In 1938, given the rise of tensions just before the Second World War in Europe, Czechoslovakia also had a gentleman’s agreement with the United Kingdom regarding the latter’s aid in case of a military invasion of the former by Germany. However, when Germany invaded Czechoslovakia, neither agreement was fulfilled, following several of the bedrock assumptions of the Realist school of thought.
Alliances, therefore, are susceptible to failure. As hard as it is for military alliances to succeed, the nuclear age amplifies the obstacles for their endurance. Even at the height of the Cold War, inside the war planning rooms of the Pentagon and the Strategic Air Command, the nuclear security assurances seemed to tremble. During the Berlin Crisis of 1961, top US officials were reconsidering whether the United States should employ nuclear weapons to defend an eventual military incursion of the USSR in West Germany. Since the development of nuclear weapons and the dominating logic of nuclear deterrence, it is perfectly reasonable to argue that security assurances in the nuclear age are quasi-empty words. In 2020, revisiting the bases of the US nuclear umbrella—particularly in Europe—does it still hold any value as a credible security assurance?
New York for Paris? The US Nuclear Umbrella Revisited
The strength of the US nuclear umbrella guarantee raised questions from the very start, most notably from France. In the 1960s, General Charles de Gaulle was highly sceptical of US nuclear security assurances, particularly after the USSR developed intercontinental ballistic missiles with enough range to reach the United States. This scepticism led de Gaulle to pose the question whether US President John F. Kennedy would be willing to risk New York for Paris. Eventually, this very lack of confidence fomented the development of France’s force de frappe—the French nuclear arsenal – allowing France to be able to protect itself and avoid a strict dependency on NATO.
The question posed by de Gaulle summarises the central issues with the credibility of US – or any – nuclear security assurances and umbrellas. In 1970, given the USSR’s massive conventional forces and its nuclear parity with the US, President Richard M. Nixon believed the nuclear umbrella was no longer sustainable. Despite his beliefs, Nixon could not publicly admit the frailty of the US nuclear umbrella lest it create anxieties in its European allies and tampers with the Cold War balance.
Fast forward to the present day, Donald Trump was elected President in 2016 with the slogan ‘America First.’ Ever since tensions have risen in the nuclear sphere in multiple fronts. President Trump, echoing President Harry S. Truman’s words from 1945, famously threatened “fire and fury” against North Korea and withdrew from the Iran Nuclear Deal. Moreover, relations with Russia have also deteriorated after the mutual withdrawal from the Intermediate Nuclear Forces Treaty and the seemingly unwillingness to extend New START—the only treaty remaining treaty limiting US and Russia’s nuclear arsenals—despite Russian President Putin’s positive signalling towards extension.
Similarly, President Trump has repeatedly shown his contempt for NATO, after moving to cut US contributions to the organisation. Despite Trump’s increased reliance on nuclear weapons and desire of a larger arsenal, it seems unlikely Trump and his ‘America First’ mentality would risk New York – or any other US city, for that matter—for Paris. The illusion of the US nuclear umbrella seems to be surfacing at last. On the other side of the Atlantic, a recent poll conducted by the Körber Foundation showed that the German population would rather either rely on France and the United Kingdom for nuclear assurances or even forgo them than to rely on the US nuclear umbrella. Notwithstanding, high-ranking military officers seem to hold on to the current regime of nuclear truth.
Sustaining the illusion of the US nuclear umbrella incurs other costs whose effects have a global reach. By perpetuating the current regime of nuclear truth, the US is selling its nuclear umbrella, using it as a rock-solid alibi to keep the United States from abiding by its disarmament commitments. Under Article VI of the NPT, each State “[…] undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament”. One key-argument against US nuclear disarmament for decades has been the anxieties it would create amongst its allies under the US nuclear umbrella.
The nuclear non-proliferation regime is already strained as it is. Arms control seems to be failing and non-nuclear weapons States are frustrated with the slow pace of disarmament efforts. The so-called ‘grand bargain’ of the NPT – non-proliferation in exchange for nuclear technology for peaceful purposes and the promise of disarmament – is in jeopardy. The maintenance and belief in the US nuclear umbrella and the growing frustration from the non-nuclear weapon States with its nuclear peers coalesce in existential threats to the cornerstone treaty keeping nuclear proliferation at bay. Were the illusion of the umbrella finally exposed, it would eliminate a key hindrance to nuclear disarmament.
The US nuclear umbrella seems to have lost its credibility. President Trump, in practicing his ‘America First’ policy has opened the blinds showing the illusion of its nuclear security assurances, particularly in the post-Cold War world. The dismantlement of the US nuclear umbrella – being replaced by a European nuclear umbrella, led by France and the United Kingdom, or eliminated completely – would likely have no de facto changes in European security. Rather, it would cripple to anti-disarmament movement in the United States. The United States is unlikely to risk New York for Paris, and its European allies seem to already know it. Waking up from this illusion would create a more inviting environment for nuclear disarmament.
 Lawrence Freedman and Jeffrey Michaels, eds. (2019), The Evolution of Nuclear Strategy. London: Palgrave Macmillan.
 Nick Ritchie (2013), Valuing and Devaluing Nuclear Weapons, Contemporary Security Policy, 34(1):152.
 Today, the US nuclear umbrella extends also to Japan, South Korea, and Australia.
 France and the United Kingdom, both NATO members, are nuclear weapons States, despite being under the US nuclear umbrella. France’s development of nuclear weapons was fomented, in part, by General Charles de Gaulle’s lack of confidence in the US nuclear umbrella. See Fred Kaplan (2020), The Bomb: Presidents, Generals, and the Secret History of Nuclear War. New York: Simon & Schuster.
 See, e.g., Hans Morgenthau (1948), Politics Among Nations. New York: A. A. Knopf; John Mearsheimer (2001), The Tragedy of Great Power Politics. New York: W. W. Norton.
 Treaty of Alliance and Friendship (1924), 23 U.N.T.C., pp. 163-169.
 See, e.g., Gerhard Weinberg (1995), A World at Arms: a Global History of World War II. Cambridge: Cambridge University Press.
 Kaplan (2020).
 James Cameron (2018), The Double Game: The Demise of America’s First Missile Defense System and the Rise of Strategic Arms Limitation. Oxford: Oxford University Press.
 Melvyn Leffler and Odd Westad, eds. (2010). The Cambridge History of the Cold War Volume II: Crises and Détente. Cambridge: Cambridge University Press.
 The Treaty on the Non-Proliferation of Nuclear Weapons (1968), 729 U.N.T.S., 173.
Orion is a doctoral researcher currently at the Department of War Studies – King’s College London. He joined the Department of War Studies in 2019, as part of the Joint PhD-programme between King’s College London and the University of São Paulo, his home institution. He holds an MA (Hons) in International Security from the University of Groningen and a BA in International Relations from the Pontifical Catholic University of Minas Gerais, with a period at the Sorbonne University – Paris XIII. His doctoral research focuses on nuclear weapons and politics, particularly the symbolism behind nuclear weapons. He analyses the overarching relationship between symbolism, identity, and behaviour within the nuclear arena, focusing on the history of US nuclear strategy post-Hiroshima.