I am heading to Toronto today for a talk this evening on NATO and its future. I don't always buy ye olde Liberal Institutionalist arguments about transaction costs and international institutions. Still, it is certainly the case here that NATO will continue to exist because it is harder to build institutions than modify them. NATO serves a variety of purposes for its members, who do not always agree about its role in the world. But as the premier multilateral security organization in the world, it ain't going anywhere.
More relevant today? I would say about as much as before. Sure, Russia's aggression makes NATO appear to be more relevant, but NATO was pretty damned relevant in Afghanistan for fourteen years or so, was very relevant in the Balkans from 1995 onwards, and very relevant for figuring out the future of Eastern Europe after 1991. I don't just say this to justify people buying the book as the book is full of comparative civil-military goodness anyway.
I will post the slides after the talk (Spoilers are bad!).