Police assistance programs have become core elements in bilateral and international security and development assistance in the post-cold- war era. International police assistance -- in the form of training, equipment, advisors, and occasionally actual police work -- has a number of goals, ranging from teaching existing police forces the norms, procedures, and values appropriate to a free-market economy and democratic politics to filling, on a temporary basis and often as part of international peacekeeping operations, the public-security void left by discredited governments and failed states in the Third World and the former Soviet sphere. Historical experience lends little support to the notion that policing can be altered significantly from the outside by international programs, but history also supplies three basic lessons. One lesson is that the domestic and international political contexts of police reform (the politics of policing) affect the design, implementation, and effectiveness of police assistance. The second lesson points to the almost intractable nature of policing, which resists change at all levels. The third lesson is that a failure to enunciate clearly, consistently, and repeatedly that democratic policing is the goal of aid, or to spell out what it looks like in practice, will lead to the re-emergence of discredited practices. 13 notes and 82 references