In my book `War at the Top of the World' I warned that the confrontation over Kashmir, the beautiful mountain state claimed by both Islamabad and Delhi, could unleash a nuclear war that could kill millions and pollute the planet.

After three wars and many clashes, it seemed the two bad neighbors had allowed the Kashmir dispute to fade into the background as their relations slightly improved.

Then came the murder last week of 26 Indian tourists at Pahalgam, a Kashmir beauty spot, by Muslim insurgents. Kashmir was roughly divided between India and Pakistan in 1947. The larger part of Kashmir was annexed by Indian troops as the entire region was scourged by massacres and rapine.

As a result, India's portion of Kashmir became the only Muslim majority state in India. Kashmiri Muslims have waged a bloody struggle since the 1980's to leave India or join Pakistan. Today, 500,000 Indian troops and an equal number of paramilitary police garrison the restive province.

I've been under fire three times on the Line of Control that separates the two Kashmirs and at 15,000 feet altitude on the remote Siachen Glacier. I was with Pakistani President Musharraf after he tried to seize Kargil which lies above Kashmir.

The outside world cared little about the India-Pakistan conflict until both Delhi and Islamabad acquired nuclear weapons. Their 'hatred of brothers', as I called it, pits fanatical Hindus against equally ardent Muslims who share centuries of hatred and are being whipped up by politicians.

Right wing Hindu militants in Delhi demand reunification of pre-1947 'Mother India.' Pakistan has about 251 million citizens; India has 1.4 billion and a much larger GDP. Pakistan would be unable to resist a full-bore attack by India's huge armed forces. So, it relies on tactical nuclear weapons to compensate for the dangerous imbalance.

But both sides nuclear arsenals are on hair-trigger alert and pointed at the subcontinent's major cities. A decade ago, the US think tank Rand Corp estimated an India-Pakistan nuclear exchange would kill three million immediately and injure 100 million. Such damage would pollute most of the region's major riverine water sources all the way down to Southeast Asia.