This chapter will examine the case of Israel and Hamas in order determine whether the pessimist thesis is warranted or whether the optimist thesis of this book, that deterrence can achieve successes not solely on the margins but on the strategic level. It defines what constitutes a success, especially when results of a given deterrence policy oftentimes fall short of a full cessation of violence. The chapter offers a background of Hamas's ideology and origins as well as a brief summary of Israel's track record of deterrence against Hamas. It examines the strategic interaction of Israel and Hamas from the outbreak of First Intifada in December 1987 until the most recent Fatah–Hamas reconciliation efforts in 2017. The chapter concludes with a summary of its findings and places the case of Israel and Hamas in the wider context of the Arab-Israeli conflict by noting similarities and differences between the cases of Israeli deterrence against the Fatah/PLO and Israeli deterrence against Hezbollah.