Defense: Testing the Shield

All week, the reports from U.S. intelligence sources were ominous. East-West tensions had reached the snapping point. The Soviet Union was mobilizing. An air strike against the U.S. and Canada was imminent. Then, on Saturday morning, came confirmation from North American Air Defense Command radar-loaded aircraft patrolling the Pacific near Midway: enemy planes were U.S.-bound.

These reports were phony. They had been planted as an elaborate preparatory touch to the biggest air-defense exercise in history—Sky Shield II. When Sky Shield II actually started last weekend, all commercial and private flying over the...