medical approaches are related to the newer ideas of supply-reduction and demand-reduction policies. There is also a third dimension to this matrix: it is useful to distinguish federal efforts from state, local, and community efforts to deal with drug use, and think of national drug control policy as being the sum of efforts that are undertaken at these different levels of government.
Perhaps the most important advance in thinking about drug policy has been the idea that instruments drawn from the different categories may complement one another in a constructive manner. Thinking in terms of complementarities leaves behind the simple dichotomies of past conceptualizations of drug policy, opening new possibilities for combining instruments in innovative ways. Complementarities can also appreciably complicate the already difficult problem of assessing the effectiveness of alternative drug-control strategies.
One aspect of thinking about complementarities combines law enforcement directed at drug users with treatment of those users. For many years it was thought that law enforcement approaches conflicted with treatment approaches. At a philosophical, ideological, or political level, this may still be true. That is, the politics of drugs tends to align those who favor law enforcement approaches as the just and effective response to drug abuse, against those who favor treatment and prevention approaches to drug abuse. Operationally, however, it is increasingly recognized that different instruments may complement one another, in the sense that each one allows the other to perform better than it could alone.
For example, law enforcement may help treatment by putting pressure on drug users to seek and remain in treatment, or by providing a direct referral source for drug users who have not yet decided to volunteer for treatment. Drug treatment may help law enforcement succeed by providing a lower cost, more effective response to drug-using offenders than jail or prison, and by softening the harsh consequences of drug law enforcement that would otherwise apply. These positive complementarities between enforcement and treatment, however, must be balanced against the possibility that efforts to coerce drug users into treatment may widen the reach and deepen the intensity of punishment.
Complementarities may also exist among drug control instruments operating at different levels of government. It may be that international and federal enforcement efforts create conditions under which local efforts to control street-level drug markets can plausibly succeed in reducing the local availability of drugs. Conversely, effective local law enforce-