The War on Drugs is an initiative undertaken by the United States to carry out an "all-out offensive" (as President Nixon described it) against the prohibited use of certain legally controlled drugs. The Congressional Research Service of the Library of Congress noted in a 1989 report that the nation's war on drugs could be considered to have started in public policy dating to November 1880, when the U.S. and China completed an agreement which prohibited the shipment of opium between the two countries. By February 1887, the 49th Congress enacted legislation making it a misdemeanor for anyone on American soil to be found guilty of violating this ban. It became officially the "war on drugs" in the 1930s, with the marijuana scare that banned possession and cultivation of cannabis (including hemp).
The "War on Drugs" has sought to cause a massive surge in cost for illicit mind-altering substances, which it has succeeded in doing, from the perspective of mark-ups, in turn raising the market value of the trade in highly targeted drugs such as cocaine and heroin to over a trillion dollars, but failed in terms of retail prices in the long term. This has had several prominent sociological, economic and political effects. A case in point is the South American country of Colombia, which had developed a commodity market to manage their imports and exports by the late 1960s. The subsequent actions taken by the American government included dumping surplus corn and grain into the Colombian market below market prices, depressing domestic production. The following decades showed a substantial rise in demand for cocaine in America. A number of economically depressed Colombian farmers in several remote areas of the country began to turn to what became a new, illicit cash crop for its high resale value and cheap manufacturing process. Local coca cultivation, however, remained comparatively minoritary in Colombia until the mid-1990s. Drug traffickers originally imported most coca base from traditional producers in Peru and Bolivia for processing in Colombia, until eradication efforts in those countries resulted in a "balloon effect".
Nixon's modern-day "War on Drugs" began in 1971. He characterized the abuse of illicit substances as "America's public enemy number one." This coincided with Colombia's destroyed domestic market, providing a fertile ground for the exploitation of the American hunger for narcotics. Thus began the rise of a culture that is still romanticized in popular media; drug cartel groups and families including Pablo Escobar's reign over Medellín became the norm in areas where the drug trade was an important part of the local economy. The political implications of the "War on Drugs" are extensive and the impact of the program has been severe.
Furthermore, according to a report released in March 2006 by the Justice Policy Institute, commissioned by the Drug Policy Alliance, America's "Drug-Free Zones" are ineffective at keeping youths away from drugs, and instead create strong racial disparities in the judicial system. 
Around the turn of the 20th century, a perception of widespread abuse of cocaine caused policy-makers in the U.S. to consider drug abuse a serious social problem rather than as cases of personal failures.
In 1988, towards the close of the Reagan Administration, the Office of National Drug Control Policy (ONDCP) was created to centrally coordinate legislative, security, diplomatic, research and health policy throughout the government. In recognition of his central role, the director of ONDCP is commonly known as the Drug Czar.
Another milestone occurred in 1996, when 56% of California voters voted yes to Proposition 215, legalizing the growing and use of marijuana for medical purposes. This act has created significant legal and policy tensions between the Federal and State governments. Courts have since decided that neither this, nor any similar acts, will protect users from federal prosecution.
It should be noted, however, that regardless of public opinion, marijuana could be the single most targeted drug in the drug war. It constitutes almost half of all drug arrests, and between 1990-2002, out of the overall drug arrests, 82% of the increase was for marijuana. In this same time period, New York experienced an increase of 2,640% for marijuana possession arrests.
United States policy
For U.S. public policy purposes, drug abuse is any personal use of a drug contrary to law. The definition includes legal pharmaceuticals if they are obtained by illegal means or used for non-medicinal purposes. This differs from what mental health professionals classify as drug abuse per the DSM-IV, which is defined as more problematic drug misuse, both of which are different from drug use.
The United States has also initiated a number of military actions as part of its "War on Drugs", such as the 1989 invasion of Panama codenamed Operation Just Cause involving 25,000 United States troops. The U.S. alleged that Gen. Manuel Noriega, head of government of Panama, was involved in drug trafficking (Panama). As part of Plan Colombia, the U.S. has funded coca eradication through private contractors such as DynCorp and helped train the Colombian armed forces to eradicate coca and fight leftwing guerrillas such as the FARC (Revolutionary Armed Forces of Colombia) and right-wing paramilitaries such as the AUC (United Self-Defense Forces of Colombia), both of which have been accused of participating in the illegal drug trade in their areas of influence.
In 2000, the Clinton administration initially waived all but one of the human rights conditions attached to Plan Colombia, considering such aid as crucial to national security at the time. Subsequently, the U.S. government certified that the Colombian government had taken steps to improve respect for human rights and to prosecute abusers among its security forces. The U.S. has later denied aid to individual Colombian military units accused of such abuses, such as the Palanquero Air Force base and the Army's XVII Brigade. Opponents of aid given to the Colombian military as part of the War on Drugs argue that the U.S. and Colombian governments primarily focus on fighting the guerrillas, devoting less attention to the paramilitaries although these have a greater degree of participation in the illicit drug industry. Critics argue that Human Rights Watch, congressional committees and other entities have documented the existence of connections between members of the Colombian military and the AUC, and that Colombian military personnel have committed human rights abuses which would make them ineligible for U.S. aid under current laws.
Another initiative that has drawn criticism is the spraying of hundreds of thousands of acres of jungle and countryside with chemical pesticides, which opponents consider to have been harmful to the environment and to many living forms in the affected areas. It is alleged that this has been counterproductive, as farmers with few available alternatives and with damaged legal crops would have continued to turn to coca cultivation despite (or, in fact, because of) repeated eradication efforts.