BBC diplomatic correspondent Jonathan Marcus discusses the renewed importance of NATO in the face of growing threats from Russia, as well as the list of countries that could join the military alliance. After Montenegro joins NATO, the alliance is unlikely to welcome in a new member for a while. Macedonia is currently blocked by Greece over the name dispute, Bosnia has a host of issues and Georgia and Ukraine are being excluded over NATO’s fears of provoking Russia. Both Sweden and Finland are pursing closer ties with NATO, but neither country has a consensus about joining the alliance.