The assassination of Ismail Haniyeh has left a vacuum in Hamas' political leadership. In the absence of a moderate voice, willing to explore diplomatic alternatives to the war with Israel, the Gaza ceasefire negotiations would be derailed.
The obvious choice for Heniyeh's successor would have been his former deputy Saleh Arouri. But Arouri was killed in an Israeli strike in Beirut in January, and the post has remained vacant ever since.
Shura council, Hamas' main decision making body, is expected to name a new chief of the political bureau soon. But Haniyeh's assassination has emboldened radical elements within the council, like Yahya Sinwar, the group's Gaza military chief. They'll have a big say in the selection of the new leader.
Khaled Mashaal, a founding member of Hamas, and Khalil al-Hayya, a close associate of Haniyeh, have emerged the front-runners for the post.
Khaled Mashaal has political and diplomatic experience, but his relations with Iran, Syria and Hezbollah soured over his support for Arab protests in 2011. But Mashaal has good relations with Turkey and Qatar and is considered a more moderate figure who headed the group until 2017.
Al-Hayya is Sinwar’s deputy who was also considered close to Haniyeh. He has important international connections with Iran, Qatar, Egypt and Turkey, and is held in good regard by the military wing. He said the killing of Haniyeh proves that Hamas would have to resort to blood and resistance against Israel and not engage in negotiations.
Nizar Abu Ramadan -- who once challenged Sinwar for the role of Gaza chief -- and Moussa Abu Marzouk, Mashaal’s deputy, are other potential candidates.
Middle-East peace negotiators are closely watching the decision, as the choice of Haniyeh's successor would be make or break for a potential Gaza ceasefire.