Addiction became a global scourge, and prohibition gradually became the norm. But outlawing these substances gave rise to the first drug-trafficking networks, which often sought to operate under state protection. These networks underwent unprecedented growth during the Cold War, when secret services used the drug trade as a political instrument. The United States paid the price for this: In 1970, one third of their troops in Vietnam were addicted to heroin. A year later, in an historic speech, President Richard Nixon launched the war on drugs.