Current US federal drug policy relies primarily on an enforcement or criminal justice model. Employed over the past three decades the central aims of the anti-drug laws are interdiction, arrest, prosecution and incarceration of users and distributors of controlled substances. These actions are perceived to be 'weapons' in the 'war against drugs'.

In general, substances designated as illegal across the US include hallucinogens (mescaline, LSD), stimulants (amphetamines, cocaine), marijuana, hashish, MDMA (ecstasy) and depressants (opium, heroin and barbiturates). The federal Controlled Substances Act establishes a series of five 'schedules' (categories) into which all controlled and prescription substances are placed. Among other drugs, heroin and marijuana are placed in Schedule I defining them as having a high potential for abuse with no accepted medical use in treatment in the US. The federal legislation does not allow Schedule I substances to be prescribed by doctors or sold in pharmacies. On the other hand Schedule II substances such as cocaine are defined as accepted for medical use 'with severe restrictions'. Schedules III, IV and V are progressively less restrictive.

Since federal laws act only as a framework for state policy, the bulk of new US drug laws are established and reformed within state legislatures. This means that even though drug users can be penalized for violating federal laws, a state government is not required to possess identical laws and a state may pass policies that conflict with federal laws. Many of the new state laws take a more liberal approach to drug policy, especially in New Mexico which stands at the forefront of drug policy reform. In step, Connecticut, Indiana, Louisiana, North Dakota and Texas overhauled drug sentencing laws in 2001. Additionally, in almost half of US states, voters can directly propose and enact new laws through the initiative and referendum process and voters in eleven states have established reform measures on such issues as civil asset forfeiture reform and marijuana for medicinal use. In an effort to move away from the 'zero-tolerance' attitude promoted by many leading politicians, education and treatment are featuring more prominently in legislation and strategy. For example, three states have enacted sweeping 'treatment instead of incarceration' legislation that mandates that anyone arrested for non-violent drug possession offenses must receive drug treatment instead of jail for their first and second offense.

In spite of such progressive changes the US drug policy as a whole remains punitive. Drug sellers, drug related crime and drug trafficking - particularly when liked to terrorism - continue to be the primary targets in America's 'war against drugs'. Consequently, vast public resources at both the federal and state levels are spent on law enforcement leaving less than 30 per cent of funds for preventative, reformative and educational programs. A growing number of individuals are arrested for drug related crimes each year. Currently around one quarter of the 2 million citizens incarcerated in US jails are charged with drug offenses. The majority of these charges are for possession, especially of marijuana. Furthermore, various state and federal laws deny former drug offenders access to public housing, loans for college, federal benefits for themselves and their children, and even the right to vote.