From the early 2000s ACO as it became had more and more activities related to the NATO Response Force. Yet after Estonia, Latvia, and Lithuania joined the alliance, and especially after the 2008 Georgia-Russia war, more attention began to be paid to NATO's core Article 5 defence obligations. The three Baltic states' worries were specifically focused on a potential Russian threat. Thus while some exercises were ostentially run to prepare the NRF, sometimes they also included Article 5 aspects. Among these dual-purpose exercises was 'Steadfast Jazz', part of the NATO Exercise Steadfast series, which was run in November 2013 across a number of NATO countries, including Poland and the Baltic states.