December 17, 1914: Congress passes the Harrison Narcotics Act, initiating federal prohibition of cocaine and opiates.
December 15, 1989: Medellin cartel leader Jose Gonzalo Rodriguez Gacha is killed by Colombian police in a raid on his Tolu ranch.
December 20, 1989: The US invades Panama with 24,000 soldiers in Operation Just Cause in order to overthrow dictator Manuel Noriega for drug trafficking, money laundering, and selling information to Cuba.
December 16, 1991: The US Supreme Court allows a US Court of Appeals ruling to stand which found that the government's interest in screening out possible drug users outweighed the applicant's constitutional right to privacy. Prior to this decision, only federal employees in occupations related to public safety (e.g. truck and bus drivers) could be tested without cause. The ruling opens the door to across-the-board drug testing for millions of businesses and was a boon to the drug testing industry.
December 18, 2002: 108 members of the European Parliament endorse a letter calling on the United Nations and its member states to establish a "system for the legal control and regulation of the production, sale and consumption of substances which are currently illegal."
December 19, 2003: Albert A. Gore III, 21, is arrested for marijuana possession after being stopped for driving a vehicle without its headlights on.
December 16, 2009: The execution of Arturo Beltran Leyva, the "Boss of Bosses," and the death of 63 others marks a record one-day high in homicides in Mexico's drug war. In 2009 alone, an average of 25 people a day -- more than one an hour -- were killed.