Collective defence and deterrence remains NATO's core purpose. Under Article V of the Washington treaty, an armed attack against any ally is considered an attack against all 28. Threat assessments and the requirement for contingency planning are reviewed as required, and are routinely considered in the North Atlantic Council, NATO's Military Committee and Allied Command Operations.
With regard to the Baltic, NATO allies continue to conduct air policing in the region, with quick reaction alert aircraft operating out of Lithuania. As part of a UK initiative, Defence Ministers agreed in June that the NATO Response Force should be given an overt Article V territorial defence role including in the three Baltic states. In this capacity, the UK would support the NATO Response Force exercising in the Baltic region.