Extended Nuclear Deterrence Revisited

By Holger Mey
1. One cannot escape nuclear reality. While nuclear weapons could, theoretically, be banned (and let’s even assume verifiably so), one cannot dis-invent scientific knowledge or technical know-how.  The genie is out of the bottle. Hence, it’s not about escaping nuclear reality, but to shape it.
2. Imagine a nuclear-free world in which formerly nuclear powers are engaged in a conventional war with each other.  Both sides have to assume that the other sidetries to secretly re-build nuclear weapons.  Hence, the incentive to initiate a clandestine nuclear program and to preempt the other side is nothing butoverwhelming. Such a nuclear re-armament race is likely to be by far more destabilizing than a situation in which both sides knew that the other side has nuclear weapons. Once a country has successfully rebuilt nuclear weapons, a pre-emptive first-strike against the other side is almost inevitable. Why wait until the other side has them?
3. Nuclear dissuasion or deterrence is likely to prevent major wars. This is, of course, hard to demonstrate,but plausibility, as well as experience, suggests that states act with caution and restraint if confronted with the risk of major destruction.
4. While states are likely to prefer to have the ultimate weapon at their disposal that guarantees their survival and independence, many states, so far,decided not to become a nuclear power. To make this point very clear: The question is less, why nations (want to) acquire nuclear weapons, but rather why shouldn’t they? Under what specific circumstances are nations prepared not to pursue the possession of weapons that would dramatically broaden their room for maneuver and, ultimately, guarantee their survival?
5. Would NATO have bombed for 78 days a capital in the Balkans, if Milosevic had had nuclear weapons and long-range delivery vehicles? After the U.S. convinced Ghaddafi to give up his nuclear weapons program and then contributed to the toppling of hisregime, how many nations would now be ready to give-up their respective nuclear weapons program?Western countries insist that they cannot accept a nuclear Iran, but the real question is what if they haveto? Why do they accept a nuclear North Korea? Quite simply, because they have to.
6. So why then are some nations actually ready to accept their non-nuclear status? Reasons range from the fact that some nations do not perceive an immanent, existential threat to their security, others simply don’t have the technological and/or financial means, and yet others enjoy security guarantees by the strongest military power on Earth, the United States of America. The extended nuclear deterrence by the U.S. to some allies is probably one of the best nuclear non-proliferation measures that exist to date.
7. For extended deterrence to be credible, a number of requirements are, if not essential, so at least most useful. First, nuclear security guarantees from a conventional superpower are much more credible than from a mid-size power. Conventional strength matters in supporting the credibility of nuclear employment options in the defense of allies. A very early recourse to nuclear weapons because of conventional weakness lacks credibility if it is about coming to help of an ally.  Second, a nuclear posture that allows for flexible, selective, and limited strikes while keeping a significant retaliatory force in reserve is a prerequisite for extending deterrence to allies. The protecting state needs alternatives to suicide or surrender.  Third, aside from offensive options,passive and active defenses are also essential. Theseinclude (i) the ability to defend against and to absorb (counter-) strikes (also here, the size of the country matters), (ii) a survivable second-strike capability, (iii) the resilience of the society, including the protection of the critical infrastructure and homeland defenses in general, and (iv) active air and ballistic missile defenses. Nobody feels protected by somebody who cannot protect himself.
8. A non-nuclear country that wants to be protected by a nuclear power and that wants to benefit from being under a nuclear umbrella also needs to fulfil a few conditions. It has to demonstrate that it is ready to share the same risks as the country it seeks nuclearprotection from. Nuclear risk sharing is best being demonstrated by nuclear weapons that are deployed on ones own territory. In case no nuclear weapons of the guaranteeing power are deployed on the soil of the ally that seeks protection and one day nuclear weapons are (re-) deployed, everyone agreed that this would send a strong political signal. However, to withdrawal existing weapons would also send a strong political signal. It would signal that the particular country (i) no longer wants to be part of a deterrence regime and no longer seeks to be under the nuclear umbrella, and (ii) would singularize the nuclear power that is ready to take huge risks just to protect an ally.
9. The 1987 INF Treaty, which banned intermediate-range ballistic missiles, did not, in fact, impose many restraints on Russian nuclear options against NATO-Europe.  However, it left non-nuclear European NATO members with dual-capable aircraft (DCA) that were increasingly in doubt to be able to penetrate Russian airspace.  Russia significantly improved their anti-access / area denial (A2AD) capability. Now that the INF treaty is being abandoned, NATO should consider deploying ground-based ballistic and cruise missiles. While from a U.S. standpoint sea-based cruise missiles would be perfectly fine, from a non-nuclear ally standpoint they would not meet the criteria of visibility and risk-sharing. Hence, deterrence theory suggests that Germany had to insist on ground-based and new air-based systems.  However, this author is under no illusions about the lack of political support for ground-based systems and another INF debate, so that the modernization of the air-based nuclear deterrent force is probably the only option left, even if insufficient from a nuclear planner’s standpoint.
10. As long as nuclear weapons exist and are part of the reality in international relations, non-nuclear members of the Alliance should do everything from their side to keep deterrence credible.