NATO's top official warned Russia on Monday to avoid another "unacceptable" crossover into Turkish airspace as Moscow widens its airstrikes in Syria to back the country's embattled government.
Washington Post: NATO warns Russia over airspace violations as Syria airstrikes widen
US Secretary of Defense Ashton Carter listens during a jointed press conference with Spanish Defense Minister Pedro Morenes (unseen) in Madrid on Oct. 5.
