As world powers face multiple crises, the one set off by a terror attack in Kashmir is getting scant attention, and little help de-escalating between two nuclear-armed neighbors.

NEW DELHI — A deadly attack on tourists in Indian-controlled Kashmir has again moved India and Pakistan closer to war as the two rivals downgraded diplomatic and trade ties, closed the main border crossing and revoked visas for each other’s nationals.

Troops from Pakistan and India exchanged fire in disputed Kashmir for a third night in a row, officials said Sunday, as relations between the nuclear-armed rivals plunged to their lowest level in years.