The challenge of building a security sector effective in terms of protecting the population and the state from challengers, and which at the same time fulfils minimum standards of good governance, was a daunting one in Afghanistan. These difficulties were compounded by what in hindsight seem to be obvious mistakes on the part of the intervention. In our paper, we investigate how security sector building fared under such adverse conditions in north-east Afghanistan. We find that in spite of the formidable challenges and the mistakes made by the international intervention, it did not fail completely. Neither did it succeed. Based on the results of quantitative surveys and qualitative research, we suggest that (a) the international intervention was partly successful in building up Afghan National Security Forces – both as a fighting force and in terms of security sector institutions that are restrained to some extent by the rule of law; (b) the problems caused by setting up informal local militias (violent feuds, criminality, human rights abuses and extortion of the population) could be partly mitigated by transforming them into an official local police programme.