Geneva/Ankara—NATO allies are struggling to ensure that Afghanistan’s main gateway, Kabul airport, remains open for urgently needed humanitarian aid flights next week when they end their evacuation airlifts and turn it over to the Taliban. The airport, a lifeline for tens of thousands of evacuees fleeing Taliban terrorists in the past two weeks and for aid arriving to relieve the impact of drought and conflict, was hit by a deadly suicide bombing outside its gates on Thursday. Turkey said it was still talking to the Taliban about providing technical help to operate the airport after the Aug. 31 deadline for troops to leave Afghanistan but said the bombing underlined the need for a Turkish force to protect any experts deployed there. Turkey has not said whether the Taliban would accept such a condition, and President Tayyip Erdogan said on Friday his country was “not in a rush to start flights” …