The test would hardly have made the news outside of India if the local air-traffic controllers had posted a warning in advance, but when an Indonesian airliner had to turn around in Indian airspace last Thursday and return to Jakarta to avoid flying into the missile's path, it was bound to draw attention. So now the whole world knows that India has test-fired a nuclear-capable missile that can hit Shanghai and Beijing, and a few people (especially in China) may be asking: Why?

The Agni-III missile failed its first flight test last July, but this one seems to have gone off very well. The missile, which reportedly can carry a 300-kiloton nuclear warhead, was not tested at its full range of more than 3,000 km on this occasion, but that is the number that gets people's attention. India's main potential enemy is Pakistan, which is right next door, and it already has missiles that can strike anywhere there. The Agni-III gives India the range to strike the Middle East (but it has no enemies there), or southern Russia and Central Asia (likewise) -- or China.

China is not India's enemy either, but there is a worrisome drift in Asian affairs, and the Agni-III is just the tip of the iceberg. To be fair, China has had missiles that could strike Indian cities for more than 30 years now (though they were actually built to reach American cities), so there is no monopoly of blame here. And neither China or India is planning to attack the other. They're just doing what comes naturally for great powers.