Contact Us

The enlargement period of NATO since 1949

Since 1949, NATO's membership has increased from 12 to 30 countries through 8 rounds of enlargement.

  • 8
  • 10
For step five, all member states, after completing their ratification processes, issue a notification to the US – which hosts the treaty – that they have accepted the protocols that envisage the accession of the new member state. When all these stages are completed in step six, the NATO secretary-general invites the new member to join the alliance. Finally, the new member completes its own national legal process and submits its accession document to the US, which has kept the Washington Treaty and becomes a NATO member.