Espionage and Intelligence Networks

France became the center of history's largest intelligence war. Every major power operated spy networks, creating a shadow world of international intrigue. The Deuxième Bureau, France's military intelligence, coordinated with Allied services while penetrating enemy operations.

Women played unprecedented intelligence roles. Louise de Bettignies, operating from Lille, ran networks providing crucial information about German troop movements. Mata Hari, the war's most famous spy, was executed in 1917, though her actual espionage remains debated. These women, operating across national boundaries, demonstrated intelligence work's international dimensions.

Neutral embassies became espionage centers. Spanish, Swiss, and Dutch diplomats transmitted messages, sheltered agents, and facilitated prisoner exchanges. The American embassy, before 1917, provided similar services. This diplomatic espionage created webs of obligation and blackmail lasting beyond war's end.