Moreover, the absence of an authoritative Palestinian interlocutor was another impediment to achieving peace through the Arab Peace Initiative.[8] The President of the Palestinian Authority, Mahmoud Abbas, supported the initiative, but Hamas leaders refrained from endorsing even the conditional readiness to recognize Israel. As part of an effort to bridge that gap and lay the foundation for a unified Palestinian delegation, pre-Summit preparations included diplomatic steps to establish a Palestinian national unity government. That government was sworn in on March 17, 2007 on the basis of the agreement reached in Mecca under the aegis of the so-called "Arab Quartet"—Saudi Arabia, Egypt, Jordan, and the United Arab Emirates.[citation needed]