He was the most successful and valued agent the United States had run inside the Soviet Union in two decades. His documents and drawings had unlocked the secrets of Soviet radars and weapons research years into the future. He had smuggled circuit boards and blueprints. His espionage put the United States in position to dominate the skies and confirmed the vulnerability of Soviet air defenses. And he had vanished.
Stuck under the battlefields near Cantigny, France, soldiers from the U.S. 1st Division took to the cavern walls to relieve what must have been terror and boredom. One sentiment carved in the rock is as timeless as it is plain: “U.S. Forever.”