Modern Diplomacy
Nuclear Proliferation and Nuclear War

Over most of the sixty years following the Cuban missile crisis, the danger of a deliberately launched nuclear war steadily declined. That, however, has been changing over the last decade. The slow deterioration at the level of major nuclear powers has now, after February 24, suddenly taken a dramatic turn. Large-scale war among major powers, unthinkable a year ago, no longer is, writes Valdai Club expert Robert Legvold.

The link between nuclear proliferation and nuclear war, and, hence, the role of the Non-proliferation Treaty (NPT) in preventing nuclear war is not simple. The direct link is not proliferation but possession—not those striving to build nuclear-weapons capabilities, but those who have them: the weapons they possess and the doctrines that guide their strategies for using them. Nuclear proliferation is the indirect link: it is the implication that were nuclear wannabes to became possessors, the increase in the number of weapons states will exponentially increase the risk of nuclear war.

But this is the simple description of the relationship. It is the state of the world at any one time that determines the effect of these first two factors—that is, what I have just described as the direct and indirect links to nuclear war. How then does this three-factor matrix, when set in motion, influence the likelihood of nuclear war?

Start with the first factor: Today’s multipolar nuclear world is opening new, more complex and dangerous pathways to nuclear war. This is happening on three levels: geopolitically the world of nuclear powers not only has swollen to nine, but it is marked by multiple tension-laden nuclear dyads (the United States and Russia, the United States and China, and India and Pakistan) and triangles (India-Pakistan-China and the United States-China-Russia). Technologically change is occurring in three spheres: the modernization or, for some, the creation of nuclear triads on land, at sea, or in the air among the five most consequential nuclear powers. The opening of new fronts: in particular, space and cyber. New Technologies—from strategic precision-strike conventional weapons to directed energy weapons, from hypersonic cruise and ballistic systems to vast advances in sensing technology, along with the integration of artificial intelligence and quantum computing. And at the conceptual level, in shifting nuclear doctrines and strategies favoring “limited nuclear options,” featuring smaller, lower-yield and more usable weapons. As a result of these converging factors, to quote William Perry, ‘The risk that nuclear weapons will be used is now as great—if not greater—than at any peak crisis moment during the Cold War.” 

As for the second factor—the link between nuclear proliferation and the risk of nuclear war: at one level it seems a long way from the 1960s’ concerns driving states toward the NPT. Then the basic impetus was a mutual US-Soviet desire to prevent West Germany from joining the nuclear club. US opposition to French acquisition had failed by 1960 and the Soviet Union’s post-1959 opposition to the Chinese program had failed by 1964, but the large remaining concern was West Germany. To secure West German acceptance of a potential NPT, the United States pushed for the Multilateral Force (MLF), the joint seaborne ballistic missile system to be manned jointly by NATO allies, including the Federal Republic. The Soviet Union objected strenuously, and the solution had two long-term consequences. First, in exchange for the US abandoning the MLF, the Soviet Union relented and accepted the US deployment of nuclear weapons in West Germany and other NATO allies, provided the weapons remained under sole US control. 

Given the Soviet Union’s original acquiescence, Russia’s subsequent objection to these weapons as a violation of the NPT rings hollow. But their presence, along with the Russian arsenal of 2,000 sub-strategic nuclear weapons in and around Europe, has created the perennial unresolved problem of how to relieve Europe from the threat they represent in a confrontation like that underway in Ukraine.

Second, the effect of nuclear non-proliferation was to intensify the NATO allies’ desire for US nuclear protection. This made extended deterrence a critical component of the US nuclear posture. And extended deterrence is a critical asymmetry that sets the US and Russian nuclear postures apart. It also vastly complicates the strategic nuclear arms control process. It arises from the fundamentally different strategic challenges facing the two countries: Russia’s is to defend the homeland; the United States’ is to defend allies. This has led Russia to its current posture designed for “Air-Space War,” and the US and its NATO allies to one defending against Russia’s growing “Anti-Access/Area Denial (A2/AD)” capability. The mismatch between the two postures not only threatens to launch the level of an inadvertent nuclear war at a much higher level, but they make weapons committed to these missions much less amenable to arms control measures. 

In the half century since the NPT was opened for signature, the nuclear non-proliferation regime has gone through several phases: from early fears of a rapid expansion in the number of nuclear powers that coincided with the nascent Brazilian and South African programs to a lesser concern over numbers and a greater concern over a specific region—the Middle East with North Korea as an outlier. Today, however, we arrive at a new point where two arrows point in the wrong direction. One is the all-to-familiar problems of a nuclear North Korea and the prospect of a nuclear Iran with all the ramifications of both for further nuclear proliferation. 

The other is suddenly new: a return to the original issue of the nuclear weaponization of US allies: This time, not only Germany, but Japan and South Korea. In Germany, of course, this prospect in the near term is remote, but if Europe is returning to another era of brute confrontation and the United States has growing preoccupations elsewhere, German thinking may change. In the case of Japan and South Korea, the mounting concern over North Korea’s aggressive nuclear plans and the rapid transformation of China’s nuclear arsenal, will surely intensify a still incipient debate over their non-nuclear status. 

Over most of the sixty years following the Cuban missile crisis, the danger of a deliberately launched nuclear war steadily declined. So did the danger of inadvertent nuclear war, with the exceptions of the bumps during the October 1973 Arab-Israeli War and the scare in fall 1983 during NATO’s Able Archer exercise. That, however, has been changing over the last decade. As noted at the outset, the danger of nuclear war raised by the direct and indirect links depends on the state of the world—particularly, on the state of relations between and among major nuclear powers. The slow deterioration at this third level has now, after February 24, suddenly taken a dramatic turn. Large-scale war among major powers, unthinkable a year ago, no longer is. 

Conceivably the risk of such a war growing out of the violence in Ukraine may have the positive effect of introducing caution into the growing strategic rivalry between the United States and China and ease the way to a more serious strategic dialogue between them, along with efforts to better manage their nuclear relationship. The ominous lessons of the Ukrainian conflict may also cause India and Pakistan as well as India and China to reconsider the fire they are playing with each time they engage arms. 

But in what is still the most critical bilateral nuclear relationship, that between the United States and Russia, the effect almost certainly will be to halt progress on nuclear arms control and destroy the prospect of the two together acting to protect, let alone, strengthen the nuclear non-proliferation regime. The strategic stability dialogue and its two working groups launched after the June Geneva summit are suspended. When serious negotiations between the two countries on controlling their increasingly ambitious nuclear weapons programs may begin is suddenly uncertain, and so too whether anything will be possible before the extended New START expires. Still more important, the risk of inadvertent nuclear war between Russia, the United States and NATO that had reappeared over the last decade but that still seemed remote, no longer does.
Views expressed are of individual Members and Contributors, rather than the Club's, unless explicitly stated otherwise.