The Palestinian militant group Hamas will likely replace Yahya Sinwar with a new political leader based outside Gaza while his brother - Mohammad Sinwar - is expected to assume a bigger role directing the war against Israel in the territory, experts say.
In its leadership deliberations, Hamas must consider not only the preferences of its main backer - Iran - but also the interests of the Gulf Arab state of Qatar, where all the main candidates to take over as politburo chief currently reside.
Sinwar, a mastermind of the Oct. 7, 2023 attack that ignited the devastating Gaza war, was killed by Israeli forces in a gun battle on Wednesday -- the second time in less than three months that Hamas has lost its top leader.
Its previous chief, Ismail Haniyeh, was assassinated in Iran in July almost certainly by Israel.
When Sinwar replaced him, he fused together both the military and political leadership in Gaza, but that does not appear likely this time around.
After more than a year of ferocious Israeli attacks that have pounded Hamas, killed thousands of its fighters and eliminated senior figures both inside and out of Gaza, it is not clear how the Islamist group will emerge from this latest blow.
Sinwar's deputy Khalil Al-Hayya, who is viewed as a potential successor, struck a defiant note on Friday, saying Israeli hostages would not be returned until Israeli troops withdrew from Gaza and the war ended.
Hamas has a history of quickly and efficiently replacing its fallen leaders, with its top decision-making body, the Shura Council, tasked with naming a new head.
The Shura Council represents all Hamas members in the Gaza Strip, the West Bank, Israeli prisons and the Palestinian diaspora, meaning the new leader should have the authority to enter ceasefire talks even if he is not in Gaza, where Hamas gunmen still hold dozens of Israelis hostage.
Besides Hayya, who is Hamas' chief negotiator, the other main leadership contenders are Khaled Meshaal, Haniyeh's predecessor, and Mohammad Darwish, a little-known figure who chairs the Shura Council, according to analysts and a Hamas source.
Hamas will need to notify Qatar, which has played a major role in rounds of so far fruitless ceasefire talks, and other regional capitals ahead of its decision, the source said.
Dividing duties
Ashraf Abouelhoul, an expert on Palestinian affairs, expected Sinwar's responsibilities to be split between two roles - one overseeing military affairs and another running the political office, responsible for international contacts and shaping policies.
"Iran is Hamas strongest ally, which supports the group with money and weapons, and their blessing is key to who becomes Sinwar's successor," said Abouelhoul, managing editor of the state-owned newspaper Al-Ahram in Egypt.
He expected Hamas to stick by core demands in future ceasefire talks, chiefly that Israeli forces withdraw from Gaza and stop the war. But it could show more flexibility on some conditions, such as the details of any deal swapping Israeli hostages for Palestinians imprisoned by Israel.
Israeli Prime Minister Benjamin Netanyahu has declared Sinwar's killing a milestone but that the war is not yet over, saying fighting would continue until the hostages are released.
Hamas was founded in 1987 and is a branch of the Sunni Islamist Muslim Brotherhood movement. Its decisions are usually taken through consensus in Hamas institutions.
With Sinwar dead, the Hamas leadership for Gaza has temporarily passed to his Qatar-based deputy, Hayya.
But the ongoing war and communication difficulties might impose limits on just how much day-to-day contact Hayya can have with men on the ground, leaving the armed wing - the Qassam Brigades - in the driving seat, experts say.
A Hamas source said Hayya was expected to encounter no problems exercising his role as "de facto Gaza leader". The source noted that Hayya had maintained good relations with the military wing and had been close to both Sinwar and Haniyeh.
Akram Attallah, a Palestinian political analyst, said he expected the armed wing to respect Hayya's authority - even from afar. He also expected Mohammad Sinwar to emerge as a more significant figure in the armed wing and in Hamas in general.
A veteran commander of the Qassam Brigades, Mohammad Sinwar has seldom appeared in public, has long been on Israel's most-wanted list and has survived several attempts on his life, Hamas sources said.
Hamas-led gunmen killed 1,200 people and abducted another 250 during the Oct. 7 attack, according to Israeli tallies. This prompted an Israeli offensive which, according to Palestinian authorities, has killed more than 42,000 Palestinians, laid waste to Gaza, and driven nearly all its population from their homes.
Sinwar's appointment in August was seen as both a show of defiance and internal unity by Hamas.
His close ties to Iran were seen as a factor supporting his candidacy. Both Darwish and Hayya are also seen as close to Tehran, whose support will be vital for Hamas to recover after the war.
Meanwhile, the prospects of the prominent former Hamas leader Khaled Meshaal have been clouded by a record of friction with Tehran after his support for the Sunni Muslim-led revolt in 2011 against Syrian President Bashar al-Assad.
Attallah said Hayya's ties to Iran stood him in better stead than Meshaal. But if Iran softened its opposition to Meshaal, he may have a chance, he said.