FILE - US soldiers take part in NATO-led Noble Partner 2017 multinational military exercises at the military base of Vaziani, outside Tbilisi, Georgia, Aug. 9, 2017. While Ukraine and Georgia aren't yet ready for NATO membership and have little prospect of being invited to join soon, the Western allies insist that NATO's doors must remain open to them. In 2008, NATO promised to eventually embrace the two nations, although it hasn't offered them a specific roadmap to membership. (AP Photo/Shakh Aivazov, File)