The celebratory commentary on the twentieth anniversary of India’s and Pakistan’s nuclear tests tip-toes around a central question: do both states actually feel more secure as a result? This question can be sidestepped, but not entirely, by praising the virtues of deterrence. Deterrence as well as common sense has indeed helped to prevent the two worst cases facing nuclear-armed adversaries — the avoidance of nuclear exchanges and full-blown conventional war. Pakistan and India have paid a lot to avoid these worst cases, while still incurring the costs of a limited conventional war in the heights above Kargil, increased live fire across contested borders and proxy warfare.

Nuclear deterrence has always had its paradoxes: the security presumed by having the Bomb is easily offset by the danger associated with its possession. The former is widely advertised; the latter is swept under the carpet. But back to our central question: does the Bomb make adversaries safer? Apparently not. If nuclear deterrence made Pakistan and India feel safer, they would have no need to seek add-ons to what was initially projected to be minimal deterrence — having just enough killing power to reinforce caution and common sense. So, here Pakistan and India stand, twenty years later, with the combined flight-testing of no less than twenty-eight types of nuclear-capable missiles and ever-rising defence budgets. Pakistan and India are not acting as if they feel safer and more secure since the 1998 tests.

Truth be told, no pairing of nuclear-armed adversaries feels safer after joining the club. Neither do they feel safer by not joining. Damned if you do and, if you live in a rough and tumble neighborhood, damned if you don’t. When the Bomb is added to a long and legitimate list of grievances, those grievances intensify. How could it be otherwise — unless national leaders are willing to offset the dangers posed by nuclear weapons with successful diplomacy.

Successful diplomacy is, alas, a rarity these days in South Asia and elsewhere. So, better to feel safe – at least on the surface – than to be sorry, and then to feel deeper in debt. The safety nuclear-armed states seek from the Bomb comes in an initial rush of invincibility, until a predictable procession of events tarnishes invincibility with doubt. It turns out that the Bomb is needy. It requires perpetual feeding, feeding that can be readily justified by the steps an adversary is taking to counter your Bomb. Nuclear enclaves are empowered by this competition, protected by national narratives equating non-support with non-allegiance to the flag.

Don’t expect the Bomb to offer “deterrence stability” — one of those fancy terms that nuclear strategists use when selling the newest bells and whistles of missile firepower. Deterrence stability just doesn’t happen in an arms competition. Deterrence stability is a frame of mind, not a numbers game. It becomes possible only when the competition seems meaningless to at least one adversary. During the Cold War, China faced the enmity of both nuclear superpowers possessing absurd numbers of nuclear weapons and nuclear war-fighting capabilities with a few dozen long-range missiles. Beijing figured that Moscow and Washington wouldn’t attack if there were a reasonable enough chance that they could be incinerated. This proved to be a wise, low cost bet.

Beijing is much richer now and friction with the United States is growing. So, Beijing is building new subs and missiles, including some that can carry more than one warhead. As is the United States and Russia. At some point, the question will again arise as to when enough is enough, and Beijing has a better track record of figuring this out than Washington and Moscow, which can’t help themselves.

“How much is enough?” was one of the foundational questions of nuclear arms control in the 1960s, and arms controllers were sorely disappointed. They won a great battle with a 1972 US-Soviet treaty banning nation-wide defences. In theory, the absence of missile defences was supposed to drain steam out of the offensive competition. Why? Since missiles would have a free ride to their targets, there would be less reason to add to their number. In practice, the prohibition on national missile defences had a barely imperceptible affect on the arms race. The competition to build up missile “counterforce” capabilities – the ability to accurately target opposing forces and military/industrial potential – had sufficient momentum on its own to carry the competition to new heights. Again, damned if you do and damned if you don’t.

Nuclear war-fighting capabilities never make adversaries feel safer and more secure. Pakistan might have already crossed this Rubicon, broadcasting military targets for its longest-(the Nicobar and Andaman Islands) and its shorter-range (counters to India’s Cold Start plans) missiles. India might go down this path as well, despite an early promise after the 1998 tests by foreign minister Jaswant Singh, who wrote in Foreign Affairs that “India shall not engage in an arms race, nor, of course, shall it subscribe to or reinvent the sterile doctrines of the Cold War.” One of these “sterile” doctrines is presumably the pursuit of nuclear war-fighting capabilities by means of counterforce targeting.

Many such promises have long been broken. Pakistani officials declared that they wouldn’t engage in an arms race, as did their Indian counterparts. Pakistani prime minister Nawaz Sharif promised not to block negotiations in Geneva on a fissile material cut-off treaty. Indian heavyweights such as K Subrahmanyam, Jasjit Singh and K Sundarji weighed in with assessments that very few nuclear weapons would be needed for stable deterrence. Sundarji, an adventurous former army chief and unapologetic booster of an Indian bomb, quipped that, for nuclear deterrence, “more is not better if less is adequate”.

Three renowned Pakistani strategic thinkers, Agha Shahi, Zulfikar Ali Khan and Abdul Sattar also debunked counterforce targeting, writing that, “Nuclear deterrence, unlike the conventional one, is not degraded by qualitative or qualitative disparity.” When Abdul Sattar became Pakistan’s foreign minister the next month, he announced that, “We shall not engage in any nuclear competition or arms race.”

To reduce nuclear dangers and to turn the page with Pakistan, Vajpayee boldly ventured to Lahore in February 1999 for a chaotic summit with Nawaz. At Lahore, they pledged to seek the resolution of the Kashmir dispute, refrain from intervening in each other’s internal affairs, engage in a composite dialogue on outstanding issues, and to negotiate confidence-building agreements and other steps to prevent conflict. Nawaz reiterated his “earnest desire to avoid an arms race” at the summit.

These pledges barely survived the Kargil War and the 2001-2 “Twin Peaks” crisis sparked by an attack on the Indian parliament by cadres of anti-India zealots. By the time of the 2008 Mumbai attacks, the Lahore Declaration was mostly a dead letter. Diplomacy to offset the rise of nuclear dangers on the Subcontinent is another dangerous pursuit.

Twenty years later, Pakistan and India stand before the next stepping-stones to their nuclear competition: multiple warhead missiles, counterforce targeting and in India’s case, missile defences. Pakistan has proven that it is willing to compete with India. The civilian leaders of India appear less enamoured with the Bomb, but they must reckon with competition from China as well as Pakistan.

These weapons are add-ons to deterrence, but not to security. This distinction is crucial, because security requires forms of reassurance that deterrence cannot provide. Deterrence is about the threat of inflicting pain; deterrence without diplomacy is not reassuring. Vajpayee’s ambitious trip to Lahore was reciprocated with Kargil. Subsequent shafts of light to improve ties have been followed by cloud cover. The optimistic estimates by top-tier strategic thinkers in India and Pakistan two decades ago that the Bomb would increase safety and security have become distant, broken dreams.

The writer is co-founder of the Stimson Center and author of 'Better Safe Than Sorry: The Ironies of Living with the Bomb'