After the terrorist attack on Indian troops in Kashmir two weeks ago that killed 40 Indian soldiers, but before Tuesday's retaliatory airstrikes across the border into Pakistan by the Indian Air Force, the Indian government did something unprecedented. It threatened to cut off Pakistan's water. Or at least, it sounded like that.

On Feb. 2, Nitin Gadkari, India's transport minister, tweeted: "Our Govt. has decided to stop our share of water which used to flow to Pakistan. We will divert water from Eastern rivers and supply it to our people in Jammu and Kashmir and Punjab." Dangerous talk: That way lies nuclear war.

In December 2001, after a Pakistan-backed terrorist attack on the Indian Parliament, there was a seminar in Karachi designed to calm everybody down. It was going quite well until somebody alleged that India had plans to use the "water weapon." At that point a Pakistani participant stated flatly that any conflict over water would lead to a nuclear first strike against India by Pakistan.