NATO

The North Atlantic Treaty Organisation, the world's largest military alliance. The Ukraine war catalysed NATO's fastest expansion since the Cold War (Finland and Sweden joined), while Trump's second term created unprecedented uncertainty about Article 5 commitments.

NATO was founded in 1949 to provide collective defence against Soviet expansion. Its Article 5 mutual defence commitment — an attack on one is an attack on all — is the foundation of the alliance. NATO expanded from 16 members in 1991 to 32 by 2024, with Finland (2023) and Sweden (2024) joining in direct response to the Ukraine invasion. Trump's repeated questioning of Article 5 obligations in his 2024 campaign created the deepest alliance uncertainty since France's 1966 withdrawal from NATO command.