Wesley Clark, NATO's former Supreme Allied Commander Europe, told Newsweek:
NATO is an organization in which nations pledge themselves together with the strongest pledge one nation can make to another, which is that an attack on one represents an attack on all. That's still the most powerful relationship between states. Among all other international organizations, there are none stronger than the relationships of NATO.
His comment on US-Russian relations is interesting as well:
I heard from Condi Rice in 2000 that the Clinton administration had somehow destroyed relations with Russia and that the new team would make things better. Now we're [talking about "resetting"] relations again.