New Delhi, April 27 -- Defence profligacy is a prerogative of rich, powerful nations. In 1983, the US embarked on its Strategic Defense Initiative, nicknamed Star Wars after a science-fiction film. Its bizarre cost-benefit equation led to it being binned within a decade.

President Donald Trump has dusted off the idea. Last week, the US Space Force reportedly awarded contracts worth $3.2 billion as part of a $185 billion Golden Dome project that aims to shield America from missile attacks. Space sensors would detect hostile launches to intercept. What kind of interceptors might orbit the planet remains unclear.

The US is bound by the Outer Space Treaty not to put weapons of mass destruction in space, but lesser weaponry may fall in a gre...