This year NATO will celebrate its 60th anniversary. So far the world's most powerful military alliance has been a remarkable success story. However, as the first decade of the new century draws to a close there appears to be a widening strategic rift among the allies. 'Two-tier NATO' is by now an established piece of shorthand in international strategic debate to indicate an 'alliance à la carte' divided into two or more factions of member states with divergent interests. Evidently, the alliance increasingly struggles to reach consensus on a whole range of strategic issues. So is NATO on a path to disintegration and, ultimately, to failure? This article argues that the organization has developed from a fixed 'two-tier' into a rather fluid 'multi-tier' alliance. On many issues the alliance is in fact divided into several different camps that are pushing in different directions. Thus, allies can be grouped into one of three tiers: a 'reformist', a 'status-quo' and a 'reversal'-oriented one. While the evolution of such a multi-tier alliance will not inevitably result in NATO's demise unmanaged, this manifestation of camps will continuously disrupt the organization's strategic agility. The article finds that if NATO is to maintain strategic vitality, it needs to develop new institutional mechanisms and establish a consensus on its strategic posture in the changing international order and to make 'variable geometry' work.