Political systems vary significantly, and there is no bigger difference than between those societies with strong states and those with weak ones—those with states that can carry out policy effectively, and those which are ineffective. This editorial is concerned with politics in societies with strong states, where the primary task is to influence the state and the secondary task is to influence other centers of power. In weak states the centers of power mostly lie outside formal governmental institutions, often with local economic elites, ethnic leaders, and international corporations and institutions.