Hamas has appointed Yahya Sinwar, its top leader in Gaza who orchestrated the deadly October 7 attack on Israel, as its new leader following the death of his predecessor in an airstrike in Iran.

This decision is certain to provoke Israel, which has prioritized Sinwar’s capture or killing after the October 7 attack, during which militants killed 1,200 people in southern Israel and took approximately 250 hostages.

In a statement, Hamas announced “the selection of Commander Yahya Sinwar as head of the movement’s political bureau, succeeding the martyred leader Ismail Haniyeh, may God have mercy on him.”

Sinwar, known for his close ties to Iran, has spent years strengthening Hamas. His promotion followed the death of Ismail Haniyeh, who was killed in an apparent bombing in Tehran. Additionally, a top Hezbollah commander was killed in Beirut last week in a presumed Israeli strike.

These killings have heightened fears of a broader conflict, potentially resulting in Israel engaging on multiple fronts.

Iran has vowed retaliation. Israel has accused Sinwar of orchestrating the deadly October 7 attack. Israeli officials believe he is hiding in Hamas’ extensive tunnel network in the Gaza Strip, using hostages as human shields.

Last week, Israel confirmed the death of Hamas’ military wing leader, Mohammed Deif, in a July airstrike in Gaza. Hamas has not confirmed his death.

Hamas’ representative in Iran, Khaled Kaddoumi, described Sinwar as a “consensus choice” popular among all factions, involved in the group’s decision-making, including negotiations. In a voice message to the Associated Press, he said Sinwar understands Palestinians’ political aspirations for a state and the return of refugees, but is also a “fierce fighter on the battlefield.”

Secretary of State Antony Blinken stated that Sinwar “has been and remains the primary decider when it comes to concluding the cease-fire.” He added that Sinwar must “decide whether to move forward with a cease-fire that manifestly will help so many Palestinians in desperate need, women, children, men who are caught in a crossfire. … It really is on him.”

Sinwar has led Hamas in Gaza since 2017, ruling with an iron grip.

In May, the International Criminal Court sought an arrest warrant against Sinwar for war crimes related to the October 7 attack, as well as against Israeli Prime Minister Benjamin Netanyahu and Israel’s defense minister for war crimes.