What are the last 10 countries to join NATO?

The Last 10 Countries to Join NATO

Since the end of the Cold War, NATO has steadily expanded, welcoming new members from Central and Eastern Europe. The most recent additions reflect the Alliance’s evolving role in ensuring security across the continent.

The last 10 countries to join NATO are: Albania, Croatia, Montenegro, North Macedonia, and several nations admitted during the major 2004 enlargement. That year saw Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia become members—an important step in integrating former Eastern Bloc countries into Western defense structures.

Albania and Croatia joined in 2009, strengthening stability in the Balkans. Montenegro followed in 2017, becoming the 29th member, despite regional tensions and opposition from some neighboring powers. North Macedonia was the most recent, officially joining in 2020 after resolving a long-standing naming dispute with Greece, which had previously blocked its accession.

Each accession reflects both a strategic decision and a political journey. Countries must meet rigorous standards, from democratic governance to military interoperability, and gain unanimous approval from all existing members. The process is not just symbolic—it represents a deep commitment to collective defense and shared values.

Today, with 31 members, NATO continues to adapt to new security challenges. While no new members have officially joined since North Macedonia, several countries—including Sweden (ratification completed in 2024) and Bosnia and Herzegovina (still in the Membership Action Plan phase)—are moving toward membership, signaling that NATO’s door remains open.

The Alliance’s growth over the past few decades isn’t just about numbers—it’s about unity, resilience, and the enduring effort to preserve peace in an unpredictable world.