Historically, states have tended to opt for one of three prostitution policy regimes: prohibition; regulation; or the abolition of state regulation with a view to providing social support to the individuals involved. This is the approach France has espoused since 1960. Nevertheless, while the state has remained committed to abolitionism, the policies and laws adopted in the name of French abolitionism have varied considerably. This coexistence of stability and change challenges current assumptions of how policy regimes behave and evolve. This is because internal policy change suggests that the regime is weak, and weak regimes that experience strong political challenges are assumed to wither away or collapse. Consequently, this article presents the historical case study of contemporary French prostitution policy, and seeks to explain how and why this policy regime has changed the way it has since World War II. It describes the three phases that have contributed to the evolution of policy in this area, from sex workers' rights protests in the mid-1970s, to the introduction of a demand-side ban on prostitution in 2016. In doing so, it explains how strong commitment to policy ideas can help sustain and otherwise weak or ineffective policy regime.