It was February 2004 and Chandar D. Sahay, then India’s top intelligence official, had just received intercepted cables sent by Pakistan-based jihadists planning a third attempt on General Pervez Musharraf’s life. Without hesitation and with his prime minister’s blessings, Mr Sahay sent the intercepts and other crucial information to General Ehsan ul-Haq, Pakistan’s intelligence chief. The assassins made their attempt. Their bid was foiled.

Such was the value placed by India on the life of the Pakistani leader that decades of distrust were set aside in that moment. Mr Sahay understood that Pakistan’s extremists had become an uncontrollable force, unmanageable by even their own creators inside Pakistan’s army and intelligence machinery. The terrorists, he reasoned, were now everyone’s problem and only joint action would get them under control.

Barack Obama reminded his Indian hosts of this reality on Monday as he addressed India’s parliament. The US president made clear that security is the cornerstone of sustainable economic growth in free societies, acknowledging that his own ambitions for the American economy would remain unfulfilled until countries such as India could grow without the fear of instability and havoc that terrorists sow.