Ruth Dreifuss is Switzerland’s former president and home affairs minister. Taking inspiration from John Marks’s heroin prescription program in the U.K., Dreifuss pioneered Switzerland’s innovative, highly effective system of heroin and methadone clinics. These clinics helped resolve the nation’s severe HIV epidemic in the 1990s and have practically eliminated many of the harms ordinarily associated with heroin addiction ever since. Moreover, the clinics are extremely popular with the Swiss public, who view them as a highly effective way of eliminating the chaotic, dangerous black market for drugs. Dreifuss demonstrates not only how countries can reverse the harmful consequences of the drug war by embracing progressive drug policies, but also how politicians can persuade their constituents—including moderates and conservatives—to support such policies.