NATO has sent invitations to Sweden and Finland to join the military alliance in its ninth enlargement so far. Since its establishment 73 years ago, NATO has expanded to 30 members from 12. The latest enlargement occurs at a time when Ukraine, Georgia, and Bosnia and Herzegovina are waiting to become members. The foundations of NATO were laid down in 1948 with the Brussels Treaty signed by Britain, France, Belgium, the Netherlands, and Luxembourg to create a collective defense alliance. A year later, with the participation of the US, Canada, Iceland, Italy, Portugal, Norway, and Denmark, the North Atlantic Treaty, more popularly known as the Washington Treaty, was signed. First enlargement with accession of Greece, Türkiye NATO has an open-door policy based on Article 10 of the treaty. The first enlargement was the accession of Türkiye and Greece on Feb. 18, 1952. The membership of West Germany on May 9, 1955 was the second and the membership of Spain in 1982 was the third expansion of the alliance. The accession of the Czech Republic, Hungary, and Poland on March 12, 1999 took the number of members to 19. The fifth enlargement process took place in 2004, with the membership of Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia. The entry of Albania and Croatia in 2009 and Montenegro in 2017 was recorded as the 7th and 8th expansion wave. The last enlargement was in 2020 with the accession of North Macedonia. NATO membership requires long, multi-step process For a country to join NATO, unanimous approval is required, which equals the approval of all 30 existing allied countries. NATO membership normally requires a long process. For this, a multi-stage process is required to be completed. Accordingly, when a country seeks to join the alliance, NATO sends an official invitation to that country. After that, a seven-step participation process begins. In the first step, NATO experts and representatives of the invited country meet in Brussels and hold talks. In these meetings, it is discussed whether the invited country meets the political, legal, and military requirements of NATO and whether it can fulfill the economic, military, legal, political, and intelligence obligations of NATO membership. Based on these negotiations, it is determined whether the invited country will reform to meet NATO terms and standards. For step two, the invited country sends an official letter of intent to the NATO secretary-general and declares that it accepts the obligations and commitments of NATO membership. If reforms are to be made, a calendar of reforms is also laid out in this letter. For step three, NATO prepares additional accession protocols to the Washington Treaty. In this way, the founding agreement of the alliance is, in a sense, updated. These protocols are signed by NATO countries. For step four, the protocols must be ratified by NATO member states in line with their national laws and procedures. The approval process differs from country to country. For example, a two-thirds vote of the Senate is required for approval in the US, while a formal vote in the UK parliament is not required. 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. 3 countries still waiting Some countries have expressed the intent to become NATO members, but their application has not yet been approved. They include Bosnia and Herzegovina, Ukraine, and Georgia. At the 2008 NATO summit in Romania's capital Bucharest, it was agreed that Georgia and Ukraine would become NATO members in the future. Since then, the two countries are called as partners as both of them are participating in the NATO operations and the alliance supports them to enhance their defense capacity. However, neither country was given a date. In 2010, the Balkan nation of Bosnia and Herzegovina was invited to NATO's Membership Action Plan.
