- May 11, 1998
India conducted three underground nuclear tests Monday, its first such tests since 1974, Prime Minister Atal Bihari Vajpayee announced. Vajpayee said the explosions in the desert 330 miles (530 km) southwest of New Delhi did not result in the release of radiation into the atmosphere. The tests were carried out at 3.45 p.m. (6.15 a.m. EDT) with a fission device, a low-yield device and a thermonuclear device.
The British Geological Survey said its equipment had picked up tremors from the tests measuring 4.7 on the Richter scale -- the equivalent of a light earthquake.
India gave no advance warnings of the nuclear tests. Since India is a not a member of the treaty, it is not obliged to submit their nuclear facilities to IAEA inspection
- May 13, 1998
India conducted two more sub-kiloton nuclear tests at Pokhran range at 1221 hours(0651 GMT).
The United States imposed economic sanctions on India for its series of underground nuclear tests. This is required by the 1994 Nuclear Proliferation Act.
- May 16, 1998
Pakistan remains elusive on nuclear testing plans. "In the face of these ominous developments, which pose an immediate threat to our security, we cannot be expected to remain complacent," Sharif said.
Earlier Saturday, Pakistan's ambassador to Russia said his country would agree to sign the Nuclear Non-Proliferation Treaty and the Comprehensive Test Ban Treaty if rival India disarms its nuclear weapons.
"India must carry out a complete nuclear disarmament under international inspection and open all its nuclear facilities to international safeguards of the International Atomic Energy Agency," said Ambassador Mansoor Alam.
- May 17, 1998
The testing series was named the Shakti (power) campaign The first blast involved a yield of 12 kilotons, and the second, a thermonuclear device, 43 kilotons, (almost three times more powerful than the bomb dropped on Hiroshima) the government said in a statement. The three others had a yield of less than one kiloton.
Pakistan's foreign minister said Sunday his country will test a nuclear device in response to India's recent tests, but he did not immediately say when Islamabad would conduct the test.
"It's a matter of when, not if, Pakistan will test. ... The decision has already been taken by Cabinet," Pakistani Foreign Minister Gohar Ayub Khan told TheAssociated Press.
"It will now be a political decision of when to test," he said. "It's not going to be in a public stadium where we will have a big bang for all to see."
- May 28, 1998
Pakistan conducted five "successful" nuclear tests on Thursday in response to the same number of tests by arch-rival India earlier this month, Pakistani Prime Minister Nawaz Sharif said in a televised address to the nation.
"We have settled the account of the nuclear blasts by India," he said referring to New Delhi's blasts on May 11 and May 13.
"Today we have successfully carried out five tests." Sharif said Pakistan had to carry out its own nuclear tests because the world community had "not done anything effective to make India realize its mistake" by conducting its tests.
Sharif did not specify the site of the nuclear tests or the strength of the devices exploded.
In announcing the explosions, Pakistan said it was giving nuclear muscle to the Ghauri missile, which it tested on April 6. The missile has a range of 900 miles, making it capable of striking most parts of India.
"The long-range Ghauri missile is already being capped with the nuclear warheads to give a befitting reply to any misadventure by the enemy," an official statement said.
The underground detonations in a remote western region of Pakistan occurred about 3:30 p.m. (1030 GMT/6:30 a.m. EDT) in the Chagai region of Pakistan's desolate southwestern Baluchistan province.
U.S.officials estimate the yield of the explosions at between five and 10 kilotons
The site is barely 50 kilometers (30 miles) from the border with Iran and Afghanistan.
President Bill Clinton announced the United States was imposing economic sanctions against Pakistan for ignoring U.S. pleas that it refrain from nuclear tests. "We have no choice but to impose sanctions," Clinton said. "I deplore the decision," Clinton said, noting that Pakistan had lost a "truly priceless opportunity" to receive U.S. economic and security assistance. Clinton made repeated appeals to Sharif - including one late Wednesday night - to refrain from joining a nuclear arms race with India, which earlier this month resumed nuclear testing and was also slapped with U.S. sanctions.
Indian Prime Minister Atal Bihari Vajpayee said the detonation of nuclear devices by neighboring Pakistan on Thursday could lead him to reconsider India's pledge not to test again.
"A new situation has come up and it will be taken into account in formulating our policy," he said when a reporter asked whether India would stick by its declared custom news moratorium on tests.
Vajpayee also said he still is committed to his policy of no first use of nuclear weapons.
- May 30, 1998
Pakistan conducted one more nuclear test Saturday, completing a series of tests, Pakistan's Foreign Secretary reported. But the Pakistani government did not say whether it plans another series of tests.
"Pakistan completed the current series by another nuclear test today. Let me clarify that there was only one test conducted," Foreign Secretary Shamshad Ahmed Khan said.
Earlier reports said Pakistan detonated two nuclear devices.
Khan told the nation that the tests were fully contained, and that no radioactivity had been released.
"The devices tested corresponded to weapons configuration compatible with delivery system," Khan said Saturday.
- Sept 18, 1998
In a report from Seismological Research Letters, India and Pakistan exaggerated the number and size of the nuclear weapons each nation detonated earlier this year, overstating the power of the atomic bombs by a factor of four.
According to the analysis two of the five nuclear explosions announced by the Indian government may never have taken place. The study also reported that only two in the series of nuclear tests that the Pakistan government announced actually involved real nuclear explosions.
- Sept 24, 1998
Pakistan's prime minister has vowed to unilaterally adhere to the nuclear test ban treaty, if the United States and other nations lift economic sanctions imposed after the country conducted nuclear tests in May.
Nawaz Sharif said Wednesday that his country was ready to adhere to the pact, even as he warned that compliance would depend on whether rival India resumed its tests.