Yaël Ronen examines the tension between the invalidity of the acts of illegal territorial regimes and their effectiveness.

Yaël Ronen is a faculty member at Sha'arei Mishpat Law College, Israel, and a former diplomat in the Israeli Foreign Service. Her areas of expertise are statehood and territorial status, international human rights law, humanitarian law and international criminal law. She is also editor of the Israel Law Review.

Part I. The Law Governing Illegal Territorial Regimes: 1. Introduction; 2. The case studies; 3. The obligation of non-recognition; Part II. Substantive Issues in Transition: 4. Treaty relations of the territory; 5. The status of settlers implanted by the illegal regime; 6. The effect of transition on the internal law of the territory; 7. Land titles granted under the illegal regime; 8. Conclusion: illegality, non-recognition and transition.