By John Ward Anderson and Kamran Khan
Washington Post Foreign Service
Sunday, May 31, 1998; Page A01

ISLAMABAD, Pakistan, May 30—Pakistan detonated another underground nuclear device today, bringing to six the number of bombs it claims to have exploded in two rounds of tests this week and threatening to increase tension with neighboring India.

India has exploded six nuclear devices -- five on May 11 and 13, in addition to one in 1974 -- raising the question of whether it will feel compelled to exceed Pakistan by conducting more tests. Such a move could lead to a nightmarish spiral of tests as the two countries, which have fought three wars in 50 years, race to stay ahead of each other.

The latest Pakistan test drew international condemnation. In a defiant, nationally televised speech announcing the test, Foreign Secretary Shamshad Ahmad, Pakistan top diplomat, lambasted world powers for ignoring the long-simmering conflict between India and Pakistan until the two had flexed their nuclear muscles and returned the prospect of nuclear war to the global agenda.

"The high priests of nonproliferation do not scratch below the surface," Ahmad said. "Their undivided focus has been and remains on nonproliferation as a concept. . . . The all-important underlying causes are conveniently ignored."

Prime Minister Nawaz Sharif, who was given a hero's welcome when he arrived in his native city, Lahore, blamed the rival tests on the continuing dispute over Kashmir, a region near the Himalayas that India and Pakistan both claim. He called on the United States and the United Nations to help resolve the problem and appeared to tie it to resolving the arms control issue in South Asia and to Pakistan's cooperation on global nonproliferation treaties.

"Until the issue of Kashmir, which is the root cause of all security problems in the subcontinent, is resolved, there will be no peace here," he said.

Ahmad said the test, which occurred at 11:55 a.m., is the last one Pakistan plans to conduct, but he did not rule out future tests. He said no radiation was released into the atmosphere but declined to provide technical data about the explosion.

The government has released no official information about Thursday's tests of what it said were five nuclear bombs. U.S. intelligence sources monitoring those blasts and the single, relatively weak seismic signal they created have questioned whether Pakistan really exploded five bombs. The day of the tests, analysts estimated that perhaps two bombs with a combined force of about six kilotons had been detonated. A kiloton is equal to the force released by 1,000 tons of TNT.

Ahmad said today that the six devices Pakistan has tested "correspond to weapons configuration compatible with delivery systems" developed by the country. Contradicting earlier comments by Foreign Minister Gohar Ayub Khan, Ahmad said that no nuclear weapons have been deployed.

The Associated Press of Pakistan reported that today's device produced a yield of 12 kilotons. Estimates of the size of the bomb dropped on Hiroshima, Japan, in 1945 range from 13 to 20 kilotons. The news service said the device was detonated at the site of the previous tests, Chagai Hills, on Pakistan's western border with Afghanistan.

In what could herald a policy shift, Ahmad said that Pakistan is considering signing two global nuclear arms agreements -- the Nuclear Non-Proliferation Treaty and the Comprehensive Test Ban Treaty -- even if India does not. Earlier, Pakistan agreed only to sign if India did so as well. Under the terms of the Comprehensive Test Ban, if India and Pakistan do not sign the treaty, it cannot go into effect.

The United States, numerous other countries and the United Nations have said they deplore the rival tests and urged India and Pakistan to join the global consensus for disarmament and nonproliferation. Both countries have been hit with punishing economic sanctions, which could cause the collapse of debt-ridden Pakistan's economy. After the first tests on Thursday, Pakistani President Rafiq Tarar declared a state of emergency and froze all foreign currency accounts to block the flight of foreign capital.

International criticism of today's test was swift.

"These tests can only serve to increase tensions in an already volatile region," President Clinton said in a statement. "Both India and Pakistan need to renounce further nuclear and missile testing immediately and take decisive steps to reverse this dangerous arms race."

"In carrying out these further tests, Pakistan has acted in flagrant disregard of international opinion," British Foreign Secretary Robin Cook said in a statement. "These tests do nothing to enhance Pakistan's security environment. They further escalate tension and heighten concerns about an arms race in South Asia."

Reaction to the latest test was mixed in the streets of Pakistan. While some people distributed sweets -- a traditional form of celebration -- others said they were bewildered and dismayed by the new test.

With an arms race and economic sanctions, "the poorest amongst the poor will suffer the most," said Kahliq Juma, a soda vendor at Karachi International Airport. "I was very happy at the time of the first test, but now I'm not so sure."

"India was wrong with its testing, and we shouldn't have followed suit," said Syed Kabir Ali Wasti, an Islamabad politician. "You shouldn't be emotional and sentimental about these things. But people were thinking we've been humiliated, insulted, and they were demoralized. So we tried to one-up them."

In addition to deep religious differences that divide Hindu-dominated India and Muslim-led Pakistan, there is an almost fanatic competitive spirit between the two countries, which were created from the partitioning of British India along religious lines when it won independence in 1947.

The competition has important psychological and political components -- reflected in the glee Indians displayed when they detonated their first bombs, and the gloom Pakistanis felt when their government waited two weeks to respond -- that could play a decisive role in whether the countries now end their tests.

After India conducted its five explosions, leaders there said they had concluded their testing and would do no more. But after Pakistan conducted its first tests two days ago, Indian Prime Minister Atal Bihar Vajpayee hinted that he might reconsider India's voluntary testing moratorium. Subsequently, however, other Indian government officials reiterated their no-test stance.

Leaders of the two countries have issued a series of contradictory statements on the nuclear issue in the last two weeks, fueling confusion and heightening mutual mistrust.

Jaswant Singh, a Vajpayee adviser on nuclear issues interviewed on Indian television today, repeated Vajpayee's comment that India is observing a testing moratorium.

"I do rather incline to a view that a great amount of the testing by Pakistan is not so much security-oriented as to send a message to the domestic public and the public opinion within the country," he said. "There is a principle involved here somewhere of equal and legitimate security. And if Pakistan thinks that this is the way for them to move towards security, well, it's their choice."

In his televised speech and in a question-and-answer period with reporters afterward, Pakistani Foreign Secretary Ahmad said that Pakistan had always planned six tests for technical reasons. "It is not a question of equalizing numbers," he said.

An aide to Prime Minister Sharif said the decision to conduct a sixth test was made after Saudi Arabia and the United Arab Emirates promised no disruption of oil supplies, and China assured Pakistan that it would review its financial and security needs -- but only after Clinton's upcoming visit to Beijing. "At present, the Chinese are too preoccupied with the sensitivities of that tour," he said.

Ahmad and Sharif seemed to explicitly tie world involvement in helping to resolve the Kashmir dispute to Pakistan's nuclear arms decisions. But it is a problem that has bedeviled Indian-Pakistani relations for generations.

Kashmir was a semi-autonomous princely state whose final status was not decided when British India was partitioned. Today, Pakistan controls about a third of Kashmir and aids Muslim insurgents on the Indian side who are trying to break free from Indian rule.

India has responded to the insurgency by pouring as many as 450,000 troops into the state of Jammu and Kashmir, according to some estimates, creating a highly militarized and tense border where machine-gun fire and rockets are traded daily.