This chapter reviews the evolution of the missile threat against Israel and the emergence of the indigenous Israeli and collaborative U.S.–Israeli missile defense response. It highlights the remarkable success achieved by the Israeli missile defense program, not only in tests and simulations but in combat. It also goes on to briefly analyze some of the vexing dilemmas in its second phase, such as who and what should get a higher level of protection, that have grown precisely as a result of these remarkable technological advances in missile defense. It concludes with a brief discussion of key implications of the Israeli introduction and operation of a multilayered missile defense system. Although some of these dilemmas and implications are specific to Israel, others may have broader relevance for other nations seriously considering the implications of missile defense.