Yahya Sinwar, shown in December, 2022, became Hamas's overall chief in August, 2024, after the killing of the Islamist movement's political leader, Ismail Haniyeh
Yahya Sinwar, shown in December, 2022, became Hamas's overall chief in August, 2024, after the killing of the Islamist movement's political leader, Ismail Haniyeh AFP

Israel's killing of Hamas leader Yahya Sinwar dealt a huge blow to the Palestinian group, and while it leaves a gaping void at the top of the movement, its militants remain determined to fight.

Sinwar masterminded the October 7, 2023 attack on Israel that sparked the Gaza war, and became the leader of Hamas in August after the death of his predecessor, Ismail Haniyeh.

While Israel has hailed Sinwar's killing as a major win, analysts say Hamas could use his legacy to mobilise a new generation of militants, who grew up suffering the consequences of Israel's retaliatory war.

Here is a look at what could come next for Hamas.

Confirming Sinwar's death in a video statement on Friday, Hamas official Khalil al-Hayya said the group was mourning the loss of its "great leader".

Sinwar's killing was not just "an extremely symbolic event" but created "a leadership vacuum in this very networked organisation", Middle East analyst Andreas Krieg of King's College London said.

His death comes little more than two months after the death in Iran of Hamas's political chief Ismail Haniyeh.

Hamas and Iran have blamed Israel for Haniyeh's death, though Israel has not offered comment.

Krieg said differences had emerged between Hamas's political leadership, in exile mostly in Qatar, and the military and operational wings in Gaza.

In July Israel also said it killed Hamas military chief Mohammed Deif in Gaza, which Hamas has denied.

"Different cells of Hamas will continue fighting, but at the core of the movement, there's a vacuum there, and that will make it very difficult to coordinate," Krieg said.

James Dorsey, of the National University of Singapore's Middle East Institute, said Sinwar was an "exceptional" figure in Hamas who enjoyed "broad support within the movement from both the political and the military wing".

Following his predecessor's death, Sinwar emerged from a field of contenders for the Hamas leadership that included relative moderates based outside of Gaza like Musa Abu Marzuk, an adviser and negotiator seen as close to Haniyeh.

Dorsey said other exiled Hamas figures like Qatar-based Hayya, close to Sinwar and lead negotiator in unsuccessful talks for a Gaza truce and hostage exchange, could once again become contenders for the top post.

Other exiled leaders who could take over, he said, include Khaled Meshaal, who served as Hamas chief until he was replaced by Haniyeh in 2017.

Sinwar's selection as leader over members of its political wing in August was widely viewed as a restructuring of the movement around armed struggle, with the focus on the war in Gaza.

Krieg said "the next leader is inevitably going to be someone from the operational level".

Should the leadership be handed to a man on the battlefield, one name has emerged as a favourite: that of Sinwar's younger brother Mohammed Sinwar.

Krieg said the brother "doesn't have the charismatic leadership appeal that Yahya had. But he has a good reputation... as a militant and fighter."

In his defiant statement on Friday, Hayya said Sinwar's death would help strengthen the movement, adding his killing had set him among "the leaders and symbols of the movement who preceded him".

Krieg said that, despite a "tactical, operational defeat" for Hamas with the killing of its leader, Sinwar's death was "not going to change armed resistance against Israel within Gaza".

Dorsey said Hamas was a movement that had "as a matter of principle proven very resilient".

"Hamas's history... is a history of Israel assassinating its leaders. Yahya Sinwar joins the list," he added.

The slain leader's legacy would "obviously" be tied to the legacy of the October 7 attack, said Dorsey.

But whether the war sparked by the attack could continue to swell Hamas's ranks has as much to do with the sheer levels of desperation in Gaza as it does with Sinwar.

"This is a generation that has lost all hope... certainly in Gaza. If you have no hope, you've got nothing and nowhere to go, you've got nothing to lose," Dorsey said.