Palestinians: The War between Mahmoud and Mohamed
The two men are now accusing each other of treason, corruption and conspiracy, prompting some Palestinians to wonder whether the time has come for U.S. Secretary of State John Kerry to make an effort to hold "peace talks" between Abbas and Dahlan.
The Abbas-Dahlan rivalry reflects growing tensions in the ruling Fatah faction, which dominates the Palestinian Authority in the West Bank.
But the war is not only between two figures. Rather, it is between two camps in Fatah representing the old guard and new guard.
There were days when Abbas and Dahlan were considered close allies and friends. When Abbas served as prime minister under Yasser Arafat, in 2003, he appointed Dahlan as Minister of Security.
Back then, Abbas and Dahlan were forced to work together to face Arafat's autocratic regime, which sought to undermine the power of the two men.
However, tensions between Abbas and Dahlan first surfaced after Hamas seized control over the Gaza Strip and drove the Palestinian Authority out of the area in the summer of 2007.
Abbas and his loyalists then held Dahlan and his forces responsible for the Hamas "coup," saying they had not done enough to prevent the defeat of the Palestinian Authority. Dahlan was a former commander of the Palestinian Preventive Security Force in the Gaza Strip.
The tensions between the two reached their peak four years ago when Abbas learned that Dahlan had been bad-mouthing the president's sons, Yasser and Tareq Abbas.
In response, Abbas ordered the Palestinian Authority security forces to raid Dahlan's residence in Ramallah and confiscate documents and various types of equipment. Some of Dahlan's friends and aides were arrested during the raid.
Dahlan was forced to flee Ramallah and has since found refuge in the United Arab Emirates.
Abbas escalated his campaign against Dahlan by persuading Fatah's Central Committee to expel him from the faction.
Abbas aides have since accused Dahlan of involvement in various crimes, including the "poisoning" of Arafat, who died in November 2004, the assassination of a number of Fatah officials in the Gaza Strip, and embezzlement of public funds.
In recent weeks, the United Arab Emirates and other Arab countries have been trying to negotiate an end to the war between Abbas and Dahlan, but to no avail.
Palestinian sources claimed that the Arab mediators had even asked the 78-year-old Abbas to appoint Dahlan, 53, as his deputy. Abbas, according to the sources, turned down the proposal, saying he would never forgive Dahlan for betraying him and Fatah.
The failure of the mediation efforts prompted Dahlan last week to launch a scathing attack on Abbas and his close aides in Ramallah, reigniting the war between the two men.
Dahlan was quoted as saying that Abbas and his team were not negotiating with Israel about the restoration of Palestinian rights, but in order to win American and Israeli backing. "The leadership of the Palestinian Authority is so weak that it can't turn down any Israeli request," Dahlan was quoted as saying.
Dahlan was also quoted as accusing unnamed Palestinian Authority officials of providing logistical aid to construction work in Jewish settlements.
Dahlan's statements have drawn strong condemnations from Abbas and his top aides. They are now referring to the ousted Fatah operative as "Lieberman Dahlan" – a reference to Israeli right-wing politician and former Foreign Minister Avigdor Lieberman, who is a strong critic of the Palestinian Authority and its leaders.
Abbas's aides are also accusing Dahlan of being part of a "conspiracy" to topple the Palestinian Authority president. They claim that Dahlan is wanted by the Palestinian Authority for his role in the assassination of Fatah activists and financial corruption.
Dahlan does not seem to be standing alone in his battle against Abbas. Several Fatah-affiliated groups and figures in the Gaza Strip and Palestinian refugee camps in Lebanon have come out in support of Dahlan, deepening divisions inside Fatah.
The war between Dahlan and Abbas has seriously undermined Fatah's credibility among Palestinians. Fatah has already lost much of its credibility as a result of its failure to reform and come up with new leaders.
This war, a weak and divided Fatah, plays into the hands of Hamas and further boosts its popularity among Palestinians. Before pursuing its efforts to achieve peace with Israel, Fatah needs to solve its internal problems. A weak and divided Fatah would never be able to sell any peace agreement with Israel to its people.