Anybody who had been following the war of words between India and Pakistan over nuclear weapons development over recent years would not have been surprised at Pakistan's decision to test five nuclear devices yesterday, only two weeks after India exploded the same number of nuclear bombs.
As long ago as 1996, Pakistani officials had stated unambiguously, when India tested Prithvi II missiles capable of carrying nuclear warheads, that they would conduct nuclear tests if India did. In a Gallup poll, 80 per cent of Pakistanis supported that stance. In September the same year both Pakistan and India refused to sign the United Nations Comprehensive Test Ban Treaty.
It was perhaps only a matter of time before Asia would find itself with two more nuclear powers.
Before now China was the only nuclear power in the region, and Beijing has not surprisingly been the severest critic of Delhi for first testing underground devices earlier this month. Relations between China and India have been dogged by suspicion and hostility for decades. They fought a brief border war in 1962.
"There has always been an atmosphere of distrust between the two countries [India and China] because the major border issue has yet to be resolved," the Indian Prime Minister, Mr Atal Behari Vajpayee, told President Clinton in a letter on May 13th. In defending the nuclear explosions, he referred to the threat of a nuclear dominance by China.
The war of underground tests between India and Pakistan has now altered the strategic balance in Asia, and China has lost its preeminence as Asia's only nuclear power. Beijing seems prepared to accept that, however deplorable, nuclear testing by Islamabad could not be prevented once India had started the nuclear arms race in the sub-continent.
China and Pakistan have enjoyed close military and diplomatic ties for many decades, and Beijing has been accused by some military analysts in the West of transferring military technology to Pakistan, though both countries deny this.
Last night, the Chinese Foreign Ministry spokesman, Mr Zhu Bangzao, expressed "deep regret" over the Pakistani tests, saying China had always advocated the complete prohibition and thorough destruction of nuclear weapons and opposed any form of nuclear proliferation.
"The Chinese government is deeply worried about this and feels uneasy about the present nuclear race in South Asia," he said, referring to the Pakistani blasts.
"We hereby call on countries concerned in South Asia to exercise the utmost restraint and to immediately abandon all nuclear weapons development programmes to avoid a further worsening of the situation and for the sake of peace and stability in the South Asian region."
Significantly, he did not make any specific criticism of Islamabad.
Speaking just a few hours before the Pakistan test explosions, Mr Zhu made it clear whom Beijing held to account.
"The current situation in South Asia was created solely by India," he said, when asked if Beijing supported or opposed nuclear testing by Pakistan.
"India, in disregard of strong international opposition, brazenly conducted nuclear tests and threatened its neighbours. The most pressing matter for the international community now is to act together to immediately demand that India abandon its plan to develop nuclear weapons and change its mistaken stance. Only in this way can the security concerns of this region be fundamentally resolved."
Because of its close relationship with Pakistan, China was considered the one country which might have been able to avert yesterday's tests, and may have tried to do so in high-level diplomatic exchanges between the two count ries.
Nevertheless, Pakistan's Foreign Ministry secretary, Mr Shamshad Ahmad, was able to say when he returned from a visit to Beijing at the weekend that China has assured Pakistan of "all-weather" friendship in the face of the threat Islamabad perceived from India's nuclear tests. In New Delhi, the Indian Prime Minister has been at pains to dampen down the row with Beijing. "Let me state categorically that we want good relations with China," he said on Monday.
"The security concerns of India cover a larger canvas. China and India have to be equally responsive to each other's concerns. We want to set a solid foundation for a stable and long-term relationship through dialogue."
Now that both New Delhi and Islamabad have tested nuclear devices, a moratorium on future testing might be attainable, diplomats in Beijing predict.
India is now asking to be accepted as a nuclear weapon state - though the five tests have not given it a nuclear strike capability by themselves - following which it would hold a moratorium on testing prior to converting this into a formal obligation through negotiations.
It has said it would also abide by some of the provisions of the United Nations Comprehensive Test Ban Treaty, and tighten government control over export of sensitive materials and technologies.
But in the interim, China and other Asian countries now face the prospect of a dangerous nuclear stand-off between two neighbours which have fought three wars since gaining independence from Britain in 1947, two of them over the Himalayan region of Kashmir.
The refusal by India and Pakistan to accept pressure from the world's five nuclear weapons nations to stay out of their elite club is a serious reversal for the policy led by the United States of "de-nuclearising" countries with nuclear weapons or weapons potential, according to a western analyst in Beijing.
The policy was successful with Khazakstan, Ukraine, Belarus, Brazil and South Africa. The United States also succeeded in persuading North Korea to freeze its nuclear programme through financial incentives, and has pushed the UN inspection of sites in Iraq for nuclear material and technology.
Unless India and Pakistan are persuaded to decommission their nuclear technology, the price India will pay for flying in the face of world opinion will be to have not one but two nuclear powers on its disputed borders, the analyst pointed out.