Historians of the Arab-Israeli conflict often describe certain episodes as a "missed opportunity" to reach an agreement between Israelis and Arabs. The problem of these descriptions, however, is that the term “missed opportunity” is not defined and mainly used for political reasons in order to blame one side in the conflict for missing the opportunity to achieve peace. The paper is part of a comprehensive research, which has been recently completed (but not yet published), on plausible missed opportunities in the Arab-Israeli conflict. The study covers some 28 successful and unsuccessful episodes of negotiations in the conflict from the first agreement signed between Faysal and Weitzman in 1919 and until the Olmert-Abu Mazen talks in 2008. The aims of this research are two-fold: First, to offer a working theoretical model of how to assess a missed opportunity. On the basis of the proposed definition, the paper will show the number of opportunities missed by Israel, the Palestinians and the Arab states. And second, to apply this definition to several case studies in the Arab-Israeli conflict. In this paper, I will mainly focus on the Arab Peace Initiative, which had been launched by the Arab Summit in Beirut in March 2002. Based on hitherto unpublished material and oral interviews, this paper will offer a historical analysis of Israeli and Arab/Palestinian behavior and decision making with regard to the Arab Peace Initiative from its launching in 2002 and until the present. The main conclusion of this paper is that Israel had indeed missed an historical opportunity to promote a dialogue with the Arab League, which could have led to a comprehensive peace agreement.