Bruno Tertrais is a Senior Research Fellow, Fondation pour la recherche stratégique, Paris, France.
No country will ever run the risk of a nuclear attack for the sake of protecting one of its allies, General Charles de Gaulle once said, thus justifying the building of an independent French deterrent.
The credibility of the US 'nuclear umbrella' was the focus of considerable debate during the Cold War, and there is no reason why this debate will not continue. But extended Western deterrence is alive and well. Not only it has survived the end of the Cold War, but its scope has even been expanded. In Europe, NATO has almost doubled in membership in the past 20 years, and the new members are keen to emphasize how much the US umbrella matters to them. (France itself now declares that, given growing European integration, its deterrent force also protects its neighbors.)
In Asia, North Korean provocations and China's military modernisation have led to a strong reaffirmation of US protection, and even to the creation of a mechanism for US-South Korean nuclear consultations. In the Gulf, the three Western nuclear powers have made new security commitments since 1990, either informally (the case of the US) or through defence agreements (in the case of France and the UK). Recently, fears of an Iranian bomb have also led the US to hint at the extension of a 'defense umbrella' over the Arabian Peninsula.
During the 2010 Nuclear Posture Review (NPR) process, the US administration was particularly careful to listen to its key allies. The NPR Report includes a strong reaffirmation of its nuclear umbrella, and discards the 'no-first-use' of nuclear weapons largely for extended deterrence reasons. Washington has also made it clear that the reason why it wants to maintain parity with Russia is that its allies would be wary of a perceived US 'nuclear inferiority'.
The usefulness of extended deterrence for non-proliferation can hardly be debated. A large body of historical evidence shows that it was the key to the renunciation of nuclear weapons by many Western countries. And if Iran was to cross the nuclear threshold, a strong reaffirmation of US guarantees will be helpful to prevent countries such as Turkey and Saudi Arabia looking for alternative options.
Extended deterrence is, however, changing. Due to technological progress, force reductions, as well as a growing allergy in many countries to nuclear weapons, it increasingly relies on non-nuclear assets such as missile defense and long-range precision strikes. Conversely, due to the evolution of the strategic landscape, it is geared towards preventing nuclear and other WMD threats more than conventional invasion.
The fact that extended deterrence will rely more on non-nuclear means will not necessarily make it less credible. As long as a state possesses nuclear weapons, its adversary has to take into account the risk, however remote, that he could ultimately face nuclear retaliation. And an emphasis on non-nuclear capabilities may in fact increase its effectiveness – relying too much on nuclear weapons can lead adversaries and allies to doubt the protector's resolve, and he himself may be 'self-deterred'.
Likewise, the fact that extended deterrence relies less on in-theatre means does not necessarily affect its credibility; deterrence is fundamentally a psychological process.
However, this also means that extended deterrence will have to be even more carefully nurtured than in the past. This is a complex exercise since it has to be credible in the eyes of three parties: the protector, the protected, and the adversary. There have been many examples of failures of extended deterrence in the past – the most egregious of which was the North Korean attack in 1950. But nowadays, the perception that Western countries are 'weak' is widespread. This can affect the value of deterrence both in the eyes of allies and of adversaries.
This calls for careful calibration of statements and declarations regarding security commitments, adapting them to various regional contexts and domestic sensitivities. This also calls for caution when decisions to alter a military posture are made for financial, political or ideological reasons – both allies and adversaries are watching.
A topical example is Europe, where many consider that nuclear weapons could be replaced with missile defense, and argue that what matters is a physical US military presence on the continent. But other believe that the withdrawal of US nuclear weapons could make the NATO deterrent less credible in the eyes of Russia or Iran, or encourage a Turkish nuclear program. (The withdrawal of US nuclear weapons from North-East Asia in 1992, largely conceived as a goodwill gesture towards Pyongyang, did nothing to prevent North Korea from going nuclear.)
Finally, Western countries should remember that the way they manage their commitments in one part of the globe can have a much broader impact. End-game decisions regarding operations in Iraq and Afghanistan, for instance, will be watched very carefully by both friends and foes.
The Nuclear Reactions column is supported by the Nuclear Security Project of the Nuclear Threat Initiative, as part of a wider partnership between the NSP and the Lowy Institute.
Photo by Flickr user ♥Unlimited.
