The village of Chapnari sits amid the Himalayan peaks surrounding Srinagar, the main city in the disputed territory of Kashmir between India and Pakistan. On June 19, 1998, two Hindu wedding parties gathered at a roadside stop in the town to wait for a hired bus that was supposed to take everyone to a combined ceremony some distance away. Most in the procession were maize farmers, and the pair of grooms wore only plastic slippers with their wedding clothes. Suddenly, five armed men emerged from a van. They ordered everyone to hand over his or her cash and jewelry. Then they lined the men up apart from the women and opened fire, cutting down the two grooms and other males as the women fled. In all, at least 25 people died in the massacre.

This episode might not appear to have much to do with Iran's pursuit of nuclear weapons. In fact, it contains a valuable lesson about how the West should view the threat from Tehran. The massacre in Chapnari was the first to follow a series of nuclear tests by Pakistan and India the month before, and from the there the bloodletting only quickened. When both countries brandished nuclear weapons in 1998, some thought it might instill a tense peace akin to the one shared by the United States and the Soviet Union during the cold war. But that didn't happen. Instead, Pakistan, emboldened by a shield of nuclear deterrence, deepened its involvement with Islamic radicals fighting as irregulars in Kashmir, and carnage of the kind in Chapnari grew more widespread. Today, some argue that Iran's leaders can be deterred from using nuclear weapons. This may well be true. But the experience of Kashmir suggests that the cost of allowing Iran to acquire nuclear arms will come not in the form of a nuclear holocaust but in an uptick in small-scale violence, particularly terrorism, throughout the Middle East.

According to statistics kept by the Institute for Conflict Management, a think tank based in New Delhi, on average roughly 130 people died per month due to terrorist violence in Kashmir in 1998 before India and Pakistan unveiled nuclear arsenals that May. Beginning in June, the average monthly body count nearly doubled. The blasts that announced India and Pakistan as the world's newest nuclear powers seemed to send a shudder of violence through the mountainous reaches of Kashmir, where insurgents backed by Pakistan have long waged a guerilla campaign to free the territory from Indian control. The rash of killings in Kashmir through the end of 1998 opened the way for a further rise of violence in the region that continued for the next three years, when casualties among insurgents, security forces, and civilians rose by 26 percent. "As the Pakistanis' nuclear capability grew, their brazenness commensurately grew," says Sumit Ganguly, the author of Conflict Unending: India-Pakistan Tensions Since 1947. "It's not just that the number of terrorist attacks in Kashmir and elsewhere in India by Pakistan increased. The sheer brazenness of them has increased as well."

Pakistan and India became a case study of cold war deterrence theory turned upside down. Violence in Kashmir rose instead of falling when the running conflict between the two nations took on a nuclear dimension. As India responded with measured counterinsurgency efforts in the region, the threat of an all-out war culminating in a nuclear exchange receded enough to allow conventional fighting to flourish. Even direct military confrontations such as artillery duels across the border between Pakistan and India rose considerably. Military skirmishes and mountain massacres suddenly seemed like small affairs in New Delhi and Islamabad compared to a nuclear war. For a time before 2001, Pakistan and India both appeared willing to stomach almost any violent episode so long as the body count fell short of the possible death toll a nuclear confrontation would bring.

Now the same effect threatens to take hold of the Middle East as Iran follows what looks to be a committed pursuit of nuclear weapons. The situation for Iran in the Middle East today is of course different in many ways than it was for Pakistan and India in South Asia in the 1990s. Most importantly, Iran is not involved in a major territorial dispute at its border. Still, there are some profound similarities to the position Iran is in now and the position of Pakistan during the 1990s. The United States stands as an existential threat at the borders of Iran as India does for Pakistan. America, like India, is a declared nuclear power, and its ally Israel, Iran's chief regional enemy, might as well be. Iranian President Mahmoud Ahmadinejad and the ruling clerics in Tehran know that a direct military confrontation with the United States or Israel will likely end badly for them, as the leaders in Pakistan knew when considering India's military dominance. In the face of this, Pakistan chose a course of terrorist aggression toward India by channeling support to Islamic militants. Pakistan actually began unleashing radical guerilla fighters in ever greater numbers with a newfound feeling of nuclear empowerment even before its weapons were ready: The spike in the number of terrorism casualties in Kashmir in 1998 followed a more gradual rise through the early 1990s.

"The Pakistanis made a very conscious decision in the late 1980s that they could start pushing the Kashmir issue much harder than they had been because they had this nuclear capability," said Paul Kapur, a visiting professor at Stanford University and author of the forthcoming book Dangerous Deterrent: Nuclear Weapons Proliferation and Conflict in South Asia. "There's a very robust positive correlation between the nuclear programs of India and Pakistan and their conflict behavior. Conflict becomes more frequent and serious as the proliferation process goes forward. This is a problem for people who argue that nuclear weapons are going to stabilize conflict relationships--because it's not necessarily true. It didn't happen here. The situation got worse."

Like Pakistan, Iran has a frightening array of Islamic militants at its disposal willing to take up attacks against the United States, Israel, or both. Iran already pursues a policy of terrorist aggression by proxy forces towards Israel with its support of groups like Hezbollah and Hamas. Those and other terrorist organizations could easily find U.S. targets in Iraq or elsewhere in the Middle East at the behest of Tehran, as could any number of Shia militias now flourishing in Iraq amid a breakdown of the state.

Whether a de facto nuclear Iran will lash out at Israel or the United States in the Middle East through the militants it supports remains uncertain. But if a nuclear Pakistan chose to do so against India, odds are good a nuclear Iran will do so against its enemies. Don't count on a revolutionary Islamic theocracy like Iran to show restraint where a regionally interested state such as Pakistan, at the time a democracy, chose belligerence. And even if Ahmadinejad and the mullahs in Tehran stay their hand, the mere idea of such a regime with a nuclear arsenal is likely to stir the imagination of Islamic fundamentalists who may act out on their own. "I think there is going to be acceleration of conventional violence in the Middle East," says Fathali Moghaddam, an Iranian-born expert in political psychology at Georgetown University. "If there is more emphasis on nuclear bombs in that region, there's no doubt about it, especially if it's coming from Iran. With a fundamentalist government in power, then I think fundamentalist Muslims will be empowered." Nuclear energy indeed.