For all his many faults, Palestinian Authority President Mahmoud Abbas has been reliable over the years as a force against violent terrorism within Palestinian society.In the wake of the unrest on the Temple Mount, however, Abbas seems to have changed course. Instead of using his influence to prevent demonstrations from deteriorating into violent clashes with Israeli forces, Abbas seems to be joining – or caving in to – more militant voices, particularly those connected with the Fatah’s Tanzim faction.In an unprecedented move, Abbas temporarily cut off military coordination with Israel in protest over a purported change in the status quo on the Temple Mount, or Haram al-Sharif as it is known by Muslims.Abbas’s change of heart raises questions not about his current standing among Palestinians but also regarding the question of leadership change, whether it be in his lifetime or after.Compounding the uncertainty is Abbas’s frail health.Over the weekend, the octogenarian was hospitalized for stress and exhaustion. Though he was released the same day, Palestinian sources said there was real concern about Abbas’s ability to continue to lead.Abbas received a phone call from Jordan’s King Abdullah to inquire about his health. A number of Palestinian officials have asked Abbas to name a successor. The Jordanian king and Palestinians in the West Bank are rightly concerned about what happens the day after Abbas. Israel should be concerned as well.Abbas has done everything in his power to prevent any single individual within Fatah from gaining power.Abbas’s choice in February of Mahmoud al Aloul as his deputy, was a clear attempt to sideline potential rivals within the organization. Aloul, a relatively unknown figure, does not threaten Abbas’s leadership the way a man like Jibril Rajoub would.Abbas has also worked tirelessly to distance Muhammad Dahlan, a former Fatah strongman in Gaza exiled to the United Arab Emirates, who continues to have influence by being a channel for Gulf State funds to Palestinians.Abbas has purged from Fatah men like Yasser Abed Rabbo, who Abbas accused of supporting Dahlan. In recent months, Abbas undermined a Palestinian prisoners’ strike led by Marwan Barghouti, who is serving five consecutive life sentences for planning terrorist attacks that killed four Israelis. Barghouti is the most popular living Palestinian public figure and Abbas seems to have been motivated by his desire to deprive him of a victory.Yet, while we know who Abbas does not want, the president has so far left no indication who he does want as successor. Israel cannot afford to wait idly until the day after. A Palestinian power struggle resulting from the vacuum in leadership left by Abbas’s passing has the potential to lead to disorder and a renewal of violence.Vying factions will inevitably attempt to garner support by calling for a popular uprising against Israel. We were witness to this dynamic during the Temple Mount crisis when members of the more radical Tanzim led by Abbas’s deputy, Aloul, called for violent clashes with Israeli forces. The most radical voices tend to set the tone when given the opportunity.That’s why it is important for Israel, preferably in behind-the-scenes talks with Jordan and Egypt, to begin pressuring Abbas to name a successor. This could help ensure a smooth transition because the chosen successor would have a vested interest in maintaining stability instead of fomenting violence. A smooth changing of the guard might present opportunities for a more pragmatic bottom-up approach to managing and ultimately solving the conflict. A new Palestinian leader backed by Jordan and Egypt might be more willing to focus on improving Palestinian lives and fostering Israeli-Palestinian cooperation. Israelis and Palestinians have recently been successful cooperating on issues such as water and electricity. Much more needs to be done.The recent unrest on the Temple Mount demonstrated the ease with which relative calm can be disrupted. The sudden departure of Abbas could create a leadership vacuum that leads to chaos and violence. Israel cannot afford to leave the matter up to chance in the hope that Palestinians will sort things out on their own. Experience has proven this does not turn out well.