Water issues impact on security at the various levels, albeit most directly on ‘human security’. Hence, it is a potential source of conflict. Following a prelude of water and ‘the human condition’, the paper presents an analytical survey of the various aspects of the water-conflict-security nexus, describing how water may cause or constitute security problems, and how conflicts and the quest for security may cause problems with water. Not only may water be a direct cause of insecurity; it may also constitute an indirect security threat by virtue of its potential for causing conflicts which may, in turn, represent security threats to states as well as societal groups and individuals. Conversely, the very ‘securitisation’ of water issues, i.e. their being referred to by relevant actors as urgent and of existential importance, may lead to conflict, as scope is thereby created for resorting to ‘extraordinary measures’ such as going to war. Based on this analysis of how water problems and conflicts are linked, the concluding sections are devoted to the question what might be done to break the vicious circles – or even better, to transform them into ‘benign circles’ where the resolution of water problems may help prevent violent conflicts and the prevention of conflict help solve water problems.