They knew which factories to burn, which bridges to blow up, which cargo ships could be sunk in good conscience. They had pothole counts for roads used for invasion and head counts for city blocks marked for incineration. They weren't just secret agents. They were secret insurance agents. These undercover underwriters gave their World War II spymasters access to a global industry that both bankrolled and, ultimately, helped bring down Adolf Hitler's Third Reich. Newly declassified U.S. intelligence files tell the remarkable story of the ultra-secret Insurance Intelligence Unit, a component of the Office of Strategic Services, a forerunner of the CIA, and its elite counterintelligence branch X-2. Though rarely numbering more than a half dozen agents, the unit gathered intelligence on the enemy's insurance industry, Nazi insurance titans and suspected collaborators in the insurance business. But, more significantly, the unit mined standard insurance records for blueprints of bomb plants, timetables of tide changes and thousands of other details about targets, from a brewery in Bangkok to a candy company in Bergedorf. They used insurance information as a weapon of war," said Greg Bradsher, a historian and National Archives expert on the declassified records. That insurance information was critical to Allied strategists, who were seeking to cripple the enemy's industrial base and batter morale by burning cities.

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