Can Loose Lips Sink an Alliance? - WSJ

NATO calls itself the most successful military alliance in human history, and that isn’t hollow bragging or crass marketing. Never before have so many countries, representing almost one-eighth of the world’s population, pledged to protect each other so consistently, for so long.

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NATO has also kept peace among centuries-old enemies. United under NATO’s security umbrella, long-feuding neighbors including France and Germany have become close allies. Others, including Greece and Turkey, have kept animosities from turning to war. Were NATO to atrophy or disappear, it isn’t inconceivable European leaders would once again fear and rearm against each other.