Two questions were paramount after the destructive power of atomic weapons was revealed. Some, depending on temperament and instinct, asked whether the capability to make such weapons might possibly be placed under international control. Others, assuming failure in this pursuit, asked how the United States could most effectively prevent further battlefield use of nuclear weapons. Lesser wars facilitated by the Bomb did not figure very much in these early deliberations. As Bernard Brodie wrote in The Absolute Weapon (1946), “One does not shoot rabbits with elephant guns, especially if there are elephants available.”

When H-bombs entered the equation, some strategic analysts began to raise the question of whether scaling up nuclear deterrence might actually increase freedom of action at lower levels of violence. For example, in 1954, B.H. Liddell Hart surmised that, “To the extent that the H-bomb reduces the likelihood of full-scale war, it increases the possibility of limited war pursued by widespread local aggression.” U.S. plans and policies for massive retaliation quickly foundered on this conundrum.

Many academics who subsequently waded into the Big Muddy of deterrence theory arrived at much the same conclusion. Glenn Snyder’s book, Deterrence and Defense, published in 1961, characterized this dilemma as follows:

The Soviets probably feel, considering the massive retaliation threat alone, that there is a range of minor ventures which they can undertake with impunity, despite the objective existence of some probability of retaliation.

Snyder returned to this theme in a chapter he wrote for Paul Seabury’s edited volume, Balance of Power (1965), noting that,

The point is often made in the strategic literature that the greater the stability of the ‘strategic’ balance of terror, the lower the stability of the overall balance at lower levels of violence.

Just about everyone who writes on this paradox, myself included, pays homage to Snyder’s essay in the Seabury book. I belatedly went back to the original, only to discover that he actually hedged his bets by adding, “…but one could argue precisely the opposite.”

Robert Jervis offered a more generalized and yet succinct formula for this paradox in The Illogic of Nuclear Strategy (1984): “To the extent that the military balance is stable at the level of all-out nuclear war, it will become less stable at lower levels of violence.” In actuality, Washington and Moscow perceived greater dangers as their nuclear competition accelerated, so the stability part of this equation turned out to be deeply suspect. But Jervis’ larger point remained valid: Adversaries possessing nuclear weapons would exercise caution to avoid major wars and any crossing of the nuclear threshold. At the same time, their “insurance policy” of nuclear retaliation provided ample leeway to engage in crisis-provoking behavior, proxy wars, and mischief making.

This construct eventually became known in the trade as the stability-instability paradox. I’m not sure who first coined this phrase or when it became common usage. If anyone knows, please send a comment.

The stability-instability paradox is most harrowing at the onset of a nuclear competition for many reasons. Troubled relations between adversaries get worse when nuclear weapons are added to their disagreements. Stability is especially hard to achieve early on, when fear and ignorance are most pronounced because adversarial moves magnify security concerns when monitoring capabilities are rudimentary, at best. In addition, the jockeying to achieve advantage – or to avoid disadvantage – is greatest early on, before tacit rules of a nuclear-tinged competition are clarified.

The U.S.-Soviet experience – admittedly, an extreme and, thankfully, lonely case — suggests that big crises are most likely to occur in the first fifteen years of a nuclear competition. Misperception and spikes in nuclear danger can still occur later on (circa 1983), but the worst passages are typically front-loaded (e.g. Berlin, Cuba, and Korea) after the Bomb’s appearance. The U.S.-Soviet case also suggests that nuclear-armed adversaries can make it through very rough patches, especially if they tacitly agree not to play with fire in each other’s back yard.

The stability-instability paradox has now hit the road and traveled to South Asia. Initially, some very distinguished observers from the region, led by K. Subrahmanyam, K. Sundarji, and Abdul Sattar, believed that going public with nuclear capabilities would serve as a stabilizing factor. The 1999 Kargil War, the 2001-2 “Twin Peaks” crisis sparked by an attack on the Indian parliament building, and the 2008 Mumbai attacks suggest otherwise. A few western analysts, including Kenneth Waltz, Sumit Ganguly, and Devin Hagerty, have argued that, because these events did not cascade into full-blown wars or nuclear exchanges, deterrence optimism is in order. Perhaps, over time, this will be the case. But Cold War conceptualizers of the stability-instability paradox never made the acquaintance of the Lashkar-i-Taiba. Until Pakistan’s security managers tacitly accept the ground rule about not playing with fire, deterrence optimists for South Asia will remain in the minority.