April 4, 1949Reputable source · 2 sourcesWell documented
NATO Is Founded
On the timeline · around April 4, 1949 ·
What happened
The United States, Canada, and ten Western European nations signed the North Atlantic Treaty in Washington, creating NATO — a collective-security alliance in which an attack on one member would be treated as an attack on all. It was the first peacetime military alliance the United States joined outside the Western Hemisphere.
Why it matters
NATO institutionalized the Western bloc and America's commitment to defend Europe, becoming the cornerstone of Cold War security in the West.