May 14 — Pakistan may detonate an underground nuclear device as early as this weekend but the test is more likely to occur next week,
               a U.S. official said today.
              “They are preparing,” an administration official said.
     Pakistan abandoned years of atomic restraint by threatening an immediate response to India’s five nuclear tests this week.
     “India’s actions, which pose an immediate and grave threat to Pakistan’s security, will not go unanswered,” Gohar Ayub Khan, Pakistan’s foreign minister, told lawmakers.
     How credible is the threat from Pakistan, a nation that’s never detonated a nuclear device, but has long boasted at an atomic capability?
     “I don’t think there’s any doubt Pakistan can do this. They’ve had the capability for several years,” says Toby Dalton, a junior fellow at the Carnegie Endowment for International Peace. “This presents the perfect opportunity to show they are a power to be reckoned with, too.”
     And that opportunity appears to be only days away.
Response Could Be Swift
Although no one doubts Pakistan’s ability to construct and detonate a nuclear device, just how soon it could do so—and whether it will—is open to debate.
     India conducted a highly ambitious gamut of nuclear tests this week, ones that would have taken roughly two months to prepare—just about as long as the newly elected Hindu nationalist Bharatiya Janata Party’s been in power. But if Pakistan wants to make a quick point, it could detonate a nuclear device within a week, experts say.
     Pakistan’s response time depends on a number of factors, including test-site readiness, the number of components needed to assemble a device, and the sophistication of the explosive, says Kevin O’Neil, deputy director of the Institute for Science and International Security
     “Statements by the Pakistanis indicate they are awaiting government orders to conduct a test and could do so within a few days,” said O’Neil. “I would take that at face value.”

"Its not a matter of if, but when"

Both Possess the Ingredients
Both subcontinental belligerents can manufacture weapons-grade material—India mostly plutonium and Pakistan mostly uranium—essential ingredients for nuclear weapons.
     And India, an original sponsor of both the Nuclear Non-Proliferation Treaty and the Comprehensive Test Ban Treaty, subsequently refused to sign either pact. Pakistan refuses to sign until India does.
     India has an estimated stockpile of about 370 kilograms of weapons-grade plutonium, enough to make roughly 75 nuclear weapons, according to the Institute for Science and International Security.
     Despite halting production of weapons-grade uranium in 1991, Pakistan has amassed some 210 kilograms, enough for roughly 10 nuclear weapons, the institute says.
     India’s nuclear arsenal is an estimated seven times larger than Pakistan’s, but David Albright, president of the institute, says Pakistan could reduce that gap, establishing an arsenal roughly half the size of India’s, within eight years.
     And that doesn’t augur well for a subcontinent on the verge of a nuclear arms race between two sworn enemies who’ve fought three wars in the past 50 years.
     “If India wanted to maintain a significant lead over Pakistan, it would be forced to dramatically increase its fissile material production,” Albright said. “Pakistan, however, is capable of matching such an increase.”