Yet, the danger of nuclear war remains "relatively small" between India and Pakistan, according to Mr Clary. "So long as there is not major ground combat along the border, the dangers of nuclear use remain relatively small and manageable," he said.

Facing mounting losses, Islamabad escalated nuclear rhetoric to draw in Washington and force a ceasefire amid escalating airstrikes, it as claimed last night.

India and Pakistan have been pushed a step closer to war after a gun massacre of tourists on April 22, their most serious confrontation in decades.