While ideology may not explain differences in welfare policy on an international comparative basis, it can help account for the process of policy development in a particular country. In Israel, ideology was very significant in the historical development of public assistance by its influence on social security policy choices concerning the removal of certain groups from the residual programme of public assistance. Indirectly, ideology also shaped the extent and type of convergence of public assistance and social insurance, as well as the relative size and scope of these two benefit systems. It had, however, relatively little influence on the subsequent operating character of the public assistance programme, which seems to have an inner logic, independent of ideology, inhering in its operating principles. The latter — local responsibility, relative liability, less eligibility and means-testing – were reinforced by the organizational character of the sponsoring agency. Because they serve as a residual programme for groups whose claim for support is not yet legitimized, public assistance programmes in most Western countries will confront the same dilemmas and acquire a similar operating character.