The first imperative is to ensure that this brazen and bloody raid on India’s most open city does not escalate into confrontation with Pakistan, the presumed origin of the attackers. Twice in 2002, following a jihadi attack on India’s parliament, the nuclear-armed rivals were within hours of open war.

Aggrieved as it justifiably feels, the Indian government of Manmohan Singh should respond to the strong peace feelers put out by Asif Ali Zardari, Pakistan’s president. Only statesmanship of a high order can prevent this tragedy from turning into a triumph for the religious right in both countries.

Equally, whether or not the terrorists were trained by Lashkar-e-Taiba – a Pakistan-based, Kashmiri jihadist group – Islamabad must retake control of its country and stop its soldiers and spies from dabbling in jihad. Elements in the ISI, Pakistani military intelligence, have played sorcerer’s apprentice to Islamist militants in Afghanistan and Kashmir. That is now undermining Pakistan – not just India. The two countries should co-operate in eradicating this scourge.

Politically, that means addressing the grievances that have stoked two decades of insurgency in Kashmir, India’s only predominantly Muslim state. But there is a more general lesson to be learned here.

There needs to be a determined push to resolve festering regional conflicts before they become stitched into a broader pattern of international confrontation.

Tackling disputes such as Kashmir, or that between Israel and the Palestinians, would help separate tractable grievances from extremist manipulation and provide the legitimacy to crush pan-Islamic jihadism.

The blunderbuss tactics of George W. Bush enabled opportunist governments – not just Israel and India but Russia (in Chechnya) and China (in Xinjiang) – to reclassify regional conflicts as part of the “global war on terror”. The advent of Barack Obama is a chance to change tack.

In parallel with a broad, robust and US-led diplomatic offensive – building legitimacy by dealing with legitimate grievances – it is time to try once again to agree on a universal definition of terrorism at United Nations level: the better to delegitimise those who use it as a weapon.

Here is one definition: terrorism is a targeted act of violence against civilians designed to have a random and multiplying effect. And that should never be legitimate.