The Founding Treaty of NATO: The Washington Treaty of 1949 (nato.int)

• The treaty was signed on 4 April 1949 by 12 countries.
• Article 5 provides for collective defense but not an automatic declaration of war.
• The treaty enshrines democratic values and consensus decision-making.

"The North Atlantic Treaty, signed on 4 April 1949 in Washington D.C., established the foundation of NATO. The 12 founding members committed to collective defense (Article 5) and consultation (Article 4). The treaty emphasizes individual liberty, democracy, and the rule of law. Negotiations lasted months, with the US securing a flexible commitment clause. The treaty remains unchanged; only accession protocols have been added."