The crisis over American missile deployment to counter the Soviet theater nuclear threat in Western Europe is only the latest symptom of a deep and recurring anxiety: How can Europeans be sure that the U.S. will be at its partners' side if Moscow launches an attack? Europeans continue to worry about that, even though the U.S. made the pledge at the beginning of the most successful defensive alliance in modern European history, the 15-nation North Atlantic Treaty Organization (NATO).
When Secretary of State Dean Acheson signed the NATO treaty on April 4, 1949, as Vice President Alben Barkley and President Harry...