NATO Membership and Defence

NATO (North Atlantic Treaty Organization) is a military and political alliance comprising countries located in Europe and North America. It was founded on 4 April 1949, when twelve countries signed the North Atlantic Treaty in Washington D.C., also known as the Washington Treaty, in that city. The organization's political headquarters is located in Brussels, Belgium.

The foundation of the alliance is Article 5 of the treaty: an armed attack on one member is considered an attack on all members. The treaty is brief—fourteen articles and slightly more than 1,000 words. Decisions are made by the North Atlantic Council, the highest political body, chaired by the Secretary General. Since 1 October 2024, the position of Secretary General has been held by Mark Rutte, former Prime Minister of the Netherlands, who is the fourteenth Secretary General.

Founding and History

The organization was created after World War II, with the aim of establishing a collective defence system linking Western Europe and North America. Article 5 has been invoked only once in the alliance's history: following the terrorist attacks of 11 September 2001 in the United States. Although invoked only once, this article forms the basis for the alliance's other defence and security operations.

Expansion and Membership

The number of members has grown substantially since 1949. Following Russia's full-scale invasion of Ukraine in 2022, Finland and Sweden—both of which had long maintained military non-alignment—applied for membership. Finland became the thirty-first member on 4 April 2023. Sweden joined on 7 March 2024, after depositing its membership documents with the United States government in Washington D.C., bringing the total number of members to thirty-two. Turkey and Hungary delayed ratification of Sweden's application, demonstrating that expansion requires approval from all members.

Ukraine, Russia, and the Conflict

Ukraine is not a member, but a specific relationship has been established. At the Washington summit in July 2024, leaders decided to create NSATU (NATO Security Assistance and Training for Ukraine), a mechanism coordinating the provision of weapons and training by members and partners to Ukraine; NSATU began operations in December 2024. In the statement from the Hague summit in June 2025, members identified Russia as a long-term threat to their collective security. Russia consistently claims that expansion and reinforcement of forces in the Baltic states, Poland, and the Black Sea region constitute a threat to its security; NATO argues that Russia poses no threat that would require it to respond to Russian actions.

Defence Spending and the Hague Summit 2025

At the leaders' meeting held in The Hague, Netherlands, on 24–25 June 2025, a commitment was made to invest annually 5 percent of gross domestic product in defence by 2035. Analysts note that this figure breaks down to 3.5 percent for baseline defence spending and 1.5 percent for capabilities and security-related expenditure. According to NATO, European members and Canada increased their defence spending by approximately 20 percent in 2025 compared to 2024 (based on actual prices using exchange rates).