India has now shown it's capable of lobbing warheads deep into China and far beyond the borders of its other longtime adversary, Pakistan. But the intermediate-range missile test early this week hurts India's security more than it helps it.
Pakistan promptly tested its own missile in response, and so the South Asia arms race goes, making the region less stable for all concerned. India's Agni II missile begets the next generation of Pakistani weapons.
It's a reason-defying cycle that sidelines the more important needs of both countries, such as enhanced educational and economic opportunity for their people.
The destructive momentum can, however, be checked. Prime Ministers Atal Bihari Vajpayee of India and Nawaz Sharif of Pakistan met in February and made substantial progress toward smoother relations, edging away from a history of warfare.
Strengthening that diplomatic initiative promises more security for both countries than missiles and warheads ever will. Indian politics is largely driving the nuclear contest, with Hindu nationalists to Mr. Vajpayee's right cheering it on. The prime minister should heed, instead, his own inner voice of reason.