From NBC News:
Pakistan declared “open war” Friday on Afghanistan, after the two South Asian neighbors traded overnight attacks in a sharp escalation of their long-running dispute.
Both sides claimed to inflict heavy damage in the renewed fighting, which threatens to further destabilize a region where terrorist groups such as the Islamic State and Al Qaeda are trying to remobilize. Tensions between the two countries, which share a 1,600-mile border, have been simmering for months as they struggle to maintain a Qatar-mediated ceasefire they reached in October, with occasional cross-border skirmishes.