First there was the Saudi-sponsored Mecca Agreement between Fatah and Hamas in February 2007. That agreement collapsed four months later when Hamas seized control over the Gaza Strip from the Fatah-dominated Palestinian Authority.Then came the Sanaa Agreement in March 2008 in Yemen. That agreement lasted only a few hours before it was pronounced dead by the two parties.The Yemeni agreement was followed by two similar reconciliation pacts that were reached under the auspices of the Egyptians. Needless to say, the Egyptian-brokered accords remained ink on paper.Today, it’s the Qataris moment to take a shot at solving the Hamas-Fatah rivalry.Qatar is hoping to replace Egypt as the major powerbroker in the Arab world, particularly in light of the fact that the Egyptians are too preoccupied with their internal problems and have apparently given up on Hamas and Fatah.Now it remains to be seen whether Qatar would be able to succeed where others failed.Given the many problems facing both Abbas and Mashaal within their own groups, it’s hard to see how the new deal could work.Abbas and Mashaal went to Qatar after they failed to implement the last Egyptian-brokered reconciliation agreement that was announced in Cairo in May 2011.The Egyptian-sponsored agreement faced many obstacles, mainly strong opposition inside both Fatah and Hamas.Abbas has been under attack by some top Fatah officials who don’t want to see Hamas incorporated into the PLO and PA. Some of these officials have even warned Abbas against holding new elections at a time when Fatah is set to suffer another defeat, as was the case in the 2006 parliamentary vote.Mashaal, too, has been facing huge challenges.First, he has been forced to leave Syria because of his refusal to support President Bashar Assad against the popular uprising that has been sweeping his country for nearly a year. Hamas leaders are today scattered in the Gaza Strip and a number of Arab countries, including Egypt and Jordan.Second, Mashaal’s overtures to Fatah and a number of “moderate” Arab countries like Jordan and Qatar have cost Hamas the political and financial backing of Iran.Third, Mashaal’s reconciliation with Fatah has alienated several top Hamas leaders in the Gaza Strip who believe he has “betrayed” the Islamist movement’s ideology and strategy.Monday’s Doha Declaration has already drawn sharp criticism from many Hamas officials and activists who expressed outrage over the idea that Abbas would serve as interim prime minister of a unity government.Some Palestinians said Monday they don’t rule out the possibility that the Qatari-engineered reconciliation accord would lead to splits inside both Fatah and Hamas.It now remains to be seen whether Abbas and Mashaal would be able to convince their followers to endorse the new deal. If they fail, the only question would be: Which Arab country would be the next to mediate between the two rival parties?