ISLAMABAD The world's oldest nuclear adversaries avoided armed conflict for fear of the potential consequences.
Its two newest nuclear powers engage in daily artillery battles.
Ever since Pakistan and India staged tit-for-tat nuclear tests in May 1998 the world has had to face the possibility the first nuclear war could erupt in one of the most crowded areas on earth.
Unlike the United States and the Soviet Union, which avoided armed conflict during a Cold War that lasted almost half a century, the armed struggle between India and Pakistan for control of Kashmir continued without a pause after the countries flexed their nuclear muscles.
"Can you imagine nuclear weapons in both hands and they have a flashpoint like this?" asked an Asian diplomat, endorsing the international pressure on the two countries to sign the treaty banning nuclear tests.
Last month a Pakistani journal, Independent Research, unemotionally said the government must be prepared to wage a nuclear war with India a Subcontinental version of the former Soviet-U.S. doctrine of mutual assured destruction, or MAD.
"It is noteworthy that a low-level Indian nuclear attack can push Pakistan back into the Cave Period, while Pakistan needs to rain at least 100 thermonuclear weapons on Indian population centers to create a somewhat similar situation," it said.
The author advocated that Pakistan stockpile enough bombs and acquire enough missiles and submarines to deliver them to ensure that a nuclear war would also turn India into an uninhabitable wasteland.
Apocalyptic Vision The positive interpretation of that apocalyptic vision is that the very danger of events spinning out of control and ending in a nuclear exchange will put a brake on conventional fighting, a limit that did not exist when the bitter foes fought full-scale wars in 1948, 1965 and 1971.
That assessment was reinforced by the struggle over Kargil last year, when infiltrators from Pakistan occupied mountain positions threatening India's supply route to its forces holding glacial northern regions of Kashmir.
Despite severe losses in inching up the slopes to drive the enemy back one by one, the Indian government steadfastly refused to escalate the conflict despite concluding the incursion was totally orchestrated by the Pakistan military command.
In a world that feared this could lead to another full-scale war, only this time between nuclear powers, India impressed foreign governments by refraining from retaliation elsewhere along the border and even banning its air force from entering Pakistani territory.
Who Controls the Bombs? That battle in the intractable Kashmir dispute underlined a key difference between India and Pakistan.
In India, the military, and hence nuclear weapons, remain firmly under the control of elected civilians.
The Pakistan army not only controls defence policy, it seized power last October in the latest of a long series of military coups.
Of all nuclear powers, Pakistan has the worst record of chronic political instability.
Its current military government faces a war in neighboring Afghanistan that has driven millions of people into Pakistan, internal political divisions, growing tension between Islamist and secular forces and severe economic problems.
There is little fear of rash actions by the current rulers, but understandably there is unease in foreign capitals about whose finger might be on the trigger in the future.
"It doesn't look good for the world if a nuclear power defaults, "said Shireen Mazari, head of the government-funded Institute of Strategic Studies, confident the International Monetary Fund will provide more funds to Pakistan because the alternative is too dangerous.
"It certainly doesn't create stability." Pakistan is conscious of the problem of control and is trying to develop a coherent nuclear doctrine, diplomats in Islamabad say.
They say Pakistani representatives have been conspicuously more active in international discussions, trying to persuade the world they are acting responsibly.
Key Force Imbalance The key problem, though, is the imbalance in the forces of India and Pakistan that could raise the pressure on Pakistan to go nuclear.
Even before a dramatic increase in military spending in the wake of the Kargil attack, India had marked superiority in the air, on the sea and in every category of land weapons. All except nuclear bombs.
According to military experts, the 1998 nuclear tests showed India, developing its own weapons, had much work to do before it could claim a dependable nuclear arsenal.
In contrast, Pakistan, using what Western experts say is a Chinese-developed and tested weapon, probably has a stockpile of usable bombs.
Having fought three wars already in their brief existence without resolving key issues, the prospect of a fourth hangs perpetually over the region.
If India unleashed the full weight of its armed forces, Pakistan with little depth or natural lines of defense might quickly see its key cities under threat and face a decision to use nuclear weapons.
"The Pakistanis themselves estimate they could last 20 days in a conventional war. It could be only 14 days if they lose their air cover," said one Western diplomat.
"At that point, all bets would be off." (Reuter)