At a secret plant in Pakistan's northern hills, nuclear technicians are believed to be working overtime in these days of crisis, producing bomb uranium around the clock, specialists say. Next door in rival India, they say, atomic warheads may already be coming out of storage.
The explosive impasse over divided Kashmir is more than a showdown between two neighbors' massed armies. It has a nuclear dimension, too, and that has the world worried.
Those who follow the Asian powers' emerging strategies doubt they will come to nuclear blows. But ultimate weapons force consideration of ultimate scenarios, and of miscalculation even by the coolest heads.
"Vajpayee could drive the Pakistanis up the wall" and into threatening a nuclear strike, said U.S. nuclear proliferation specialist David Albright. "The Pakistanis know they're completely outgunned."
India's prime minister, Atal Bihari Vajpayee, this week ratcheted up tension over Kashmir, claimed by both countries, by rallying his troops with words of war, talk of preparing "for decisive victory against the enemy." Passions had risen days earlier when 34 people, mostly Indian soldiers' wives and children, were killed in a Kashmir raid by suspected Islamic militants from Pakistan.
It was a back-to-back series of bomb tests in 1998 that announced to the world that Pakistan and India, enemies in three wars since 1947, were now both nuclear powers. India has since declared a policy of no first use of atomic weapons, but Pakistan, whose army is half the size of India's, has not foresworn "going nuclear" first in a war.
"This is Pakistan's trump card," Miriam Rajkumar, an Indian analyst at Washington's Carnegie Endowment for International Peace, said in an interview.
Albright said the Indians are believed to have so far produced 50 to 100 plutonium-core nuclear warheads, and the Pakistanis 30 to 50 using the other bomb material, highly enriched uranium. Some specialists think the Indians have no more than 50 devices.
Each warhead's average destructive power is probably equivalent to the U.S. atomic bomb dropped on Hiroshima in 1945, that is, around 15 kilotons, or 15,000 tons of TNT, said Albright, a physicist with the Washington-based Institute for Science and International Security.
The Indians would be expected to mount the bombs on their Russian-made MiG warplanes, and the Pakistanis to rely more on missiles, including Chinese-made M-11s, with a range of 190 miles.
Albright said that as the crisis deepens, "I think both may be mounting warheads now."
Pakistani physicist Zia Mian said the two nations are in a race to expand their arsenals. "The Pakistani uranium enrichment facilities, as far as we know, are working three shifts, around the clock," he said.
Like others, Mian, of Princeton University, said the scenario likeliest to provoke a Pakistani nuclear strike would be a "last stand" in which national survival is threatened by a deep Indian military thrust or by a strangling naval blockade.
Political scientist Sumit Ganguly agreed. "If the Indians made an incursion deep into Pakistan and didn't show signs of stopping, then the Pakistanis might threaten the use of nuclear weapons," said the author of "Conflict Unending," a new book on the India-Pakistan wars.
But the University of Texas scholar said that "everything about Indian military culture speaks of care and prudence," and his fellow Indians wouldn't be "that stupid," to provoke nuclear retaliation.
In a way, Kashmir may be the "safest place" for a war, Mian said, since it holds no strategic Pakistani targets and the mountainous terrain would discourage a massive Indian armored offensive.
A nuclear war could leave 30 million Indians and Pakistanis dead, the Washington-based Natural Resources Defense Council determined last January via a computer model of a full-scale exchange. The model envisioned a dozen warheads striking large cities in each nation. It did not project long-term deaths from radiation cancers.
Before such an exchange occurred, some Indian analysts say, a greater power — the United States — would step in at the last minute to take control of Pakistan's weapons. Carnegie's Rajkumar calls that a "dangerous" assumption. "Wishful thinking," said Mian.
But world powers do have a heavy stake in the Asian subcontinent, Albright noted. Family and business ties to the region grow deeper every year, especially for America and Britain. The shock waves of a Muslim-versus-non-Muslim conflict would reverberate across the Middle East and Asia, including in Afghanistan. Even taxpayers in the West would feel the impact.
"A callous reaction is, `So what? Let them nuke each other. Millions die and they can pick up the pieces,"' Albright said. But in the end, he said, "I expect we would have to pay to reconstitute their societies."