NATO: the North Atlantic Treaty, 32 members and the collective defence of Article 5
Background
The North Atlantic Treaty was signed on 4 April 1949 by 12 founding countries. NATO now has 32 members, the latest being Finland (4 April 2023) and Sweden (7 March 2024). Article 5 says an armed attack against one member is an attack against all. Article 10 lets any European State that can further the treaty's principles join. The headquarters is in Brussels. Bosnia and Herzegovina, Georgia and Ukraine are listed as aspiring members.
Members:
32
Founding members:
12
Headquarters:
Brussels
Why it matters for exams: NATO's structure, membership and Article 5 are perennial questions on international organisations.
Kerala PSCUPSC