When India tested its atomic bomb in May of last year, Pakistan responded swiftly with five tests of its own. The launch of India's Agni II ballistic missile on Sunday has virtually guaranteed that Pakistan will stage a test firing of its own Ghauri or Shaheen rockets. The head of Pakistan's armed forces, Gen Pervez Musharraf, could hardly have been more specific on this when he announced that "no Indian should have any doubt that we cannot respond. We have all the capabilities."
There is little new in India and Pakistan rattling their respective sabres. The two countries have fought short wars since the partition of the sub-continent in 1947. But in recent months there has been a rapprochement and there is reason to believe that little more than rhetoric is involved in the current exchanges.
The Agni II launch, many observers believe, was a shot across the bows, not of Pakistan but of China, which has a disputed border with India. The rocket's range of 2,500 kilometres has brought a large area of China within reach of India's nuclear capability and the Indian media have been quick to point this out.
China, which fought a brief border war with India in 1962, is to resume talks on the disputed region next month and India feels that Sunday's launch will have strengthened its hand against its formidable neighbour.
Beijing, not surprisingly, has reacted angrily, especially in the context of the statement last year in which India's foreign minister, Mr George Fernandes, described China as India's greatest enemy.
Criticism of India's nuclear weapons programme by the United States and western countries has been met with sharp anti-NATO responses. The Hindu newspaper in a commentary yesterday wrote: "It will be a cruel irony if those responsible for blatant violation of international law and norms, and threatening world peace, take exception to India's efforts to cope with its threat-perceptions." Clearly it will take extremely severe pressure to deter India from further developing its rocketry until it possesses a full Intercontinental Ballistic Missile capability to strike at targets up to 5,000 kilometres away.
Suggestions that the Agni II launch may have been merely a political ploy for internal consumption by prime minister Athal Behari Vajpayee, are short of the mark. The coalition government led by Mr Vajpayee's BJP party has, admittedly, been under pressure but it is unlikely that this will be significantly eased by this move. In fact the launch had been scheduled for last month and postponed following US pressure. It had to take place by the end of April to avoid even longer postponement as the monsoon season sets in.
There is, fortunately, still time for successful moves to stem the proliferation of nuclear arms in south Asia. There is a long time-gap between the testing of rockets and their actual deployment and the missile development programmes of both major states on the Indian sub-continent have been beset by technical difficulties. It is to be expected that western powers will take advantage of the time available to them to persuade India and Pakistan to abandon this arms race.