Pakistan’s airstrikes in Afghanistan showed its overwhelming superiority in conventional warfare, but the Taliban have refined a lethal repertoire of guerrilla tactics.

Afghanistan and Pakistan are fighting again, trading deadly shelling and mortar fire across their rugged border, with Pakistan’s defense minister saying his country’s patience had “run out” and declaring “open war” on its Taliban-run neighbor.

Fighting between Pakistan and Afghanistan has continued for a third day, even as diplomatic efforts intensify, with the international community calling for urgent talks. Islamabad says its forces have killed more than 300 Afghan troops,