Final answer:
Norway and Turkey are two countries that are members of NATO but not the EU. Norway has been part of NATO since its inception in 1949, and Turkey joined in 1952. Both participate in NATO's collective defense mandate but are not EU members.
Step-by-step explanation:
Two countries that are members of NATO but not part of the European Union (EU) are Norway and Turkey. Norway joined NATO early on in 1949 as a founding member of the organization.
Turkey became part of NATO in 1952. Both countries actively participate in collective defense and security operations but have chosen to either not join the EU (Norway) or have not been admitted (Turkey). While the UK was previously in the EU, it has since left, making it another notable country that belongs to NATO but not the EU.
NATO's primary goal has always been to secure peace in Europe, especially during the tense periods of the Cold War. The organization was established after World War II as Western European nations and the United States sought to counteract the threat of communist expansion and the Soviet Union's influence.
Article 5 of the NATO Treaty signified a promise among member states for collective defense, setting a precedent that an attack on one is an attack on all, thus creating a significant military alliance that extends beyond European borders to include North America. This principle of collective security is at the heart of NATO's enduring strategy for maintaining international peace and stability.