Yahya Sinwar, appointed as the leader of Hamas on Tuesday, orchestrated the deadliest attack on Jews since the Holocaust. Sinwar, who spent nearly half his life in Israeli prisons, has openly expressed his intent to strike Israel hard.
In December 2022, Sinwar announced at a rally in Gaza that Hamas would unleash a “flood” of fighters and rockets against Israel, a speech initially perceived as hyperbolic.
“We will come to you, God willing, in a roaring flood. We will come to you with endless rockets, we will come to you in a limitless flood of soldiers, we will come to you with millions of our people, like the repeating tide,” Sinwar proclaimed.
Less than a year later, on October 7, 2023, Hamas fighters breached Gaza’s fence, launching an attack that resulted in the deaths of 1,200 people, the capture of 152 hostages, and a blow to Israel’s reputation of invincibility.
Before his recent appointment, Sinwar was the chief of Hamas in Gaza. He started as a ruthless enforcer against collaborators with Israel and rose to leadership after his release from prison in 2011. Following the attack, the prosecutor sought arrest warrants for Sinwar, Mohammed Deif, another Hamas figure, Israeli Prime Minister Benjamin Netanyahu, and his defense chief over the response, which devastated much of Gaza. Both Israel and Hamas dismissed the accusations and objected to being equated with each other, despite facing different charges.
Sinwar’s December 2022 speech foreshadowed the “flood of Al-Aqsa” attack, named after the Al-Aqsa mosque in Jerusalem, a site of repeated Israeli raids. Sinwar did not appear publicly after the October 7 attacks but directed operations with Deif and another commander. He also led prisoner-hostage swap negotiations, possibly from bunkers beneath Gaza. Freed hostages reported seeing Sinwar in the tunnels, though neither Hamas nor Israeli officials confirmed this.
The issue of hostages is personal for Sinwar, who spent 23 years in Israeli prisons and vowed to free all Palestinian prisoners. He was one of 1,027 Palestinians released in a 2011 swap for a single Israeli soldier.
Born in Khan Younis refugee camp, Sinwar was elected as Hamas’ Gaza leader in 2017. Following the October 7 attacks, Israeli Defense Minister Yoav Gallant said Sinwar and other leaders were “living on borrowed time.”
Sinwar gained prominence as the head of the Al-Majd security apparatus, targeting Palestinians accused of collaborating with Israel. Both Hamas leaders and Israeli officials agree on Sinwar’s extraordinary devotion to the movement. A Hamas figure in Lebanon described him as “puritanical” with exceptional endurance, while Michael Koubi, a former Shin Bet official, noted Sinwar’s ability to intimidate and command.
Sinwar, arrested in 1988, was sentenced to consecutive life terms for planning the abduction and murder of two Israeli soldiers and four Palestinians. In prison, he continued his hard line against collaborators. Israelis who dealt with him reported that Sinwar, despite not having Jewish blood on his hands, had Palestinian blood on his hands.
Yuval Bitton, former head of the Israel Prison Service’s intelligence division, recalled that Israeli medics removed a tumor from Sinwar’s brain in 2004. Bitton, whose nephew was killed in the October 7 attack, remarked, “We saved his life and this is his thanks.”
Koubi described Sinwar as devoted to the destruction of Israel and killing Jews, labeling him a “psychopath” who grasps reality differently from more rational terrorists. Bitton added that Sinwar was willing to endure significant suffering for his cause, even leading a mass hunger strike in prison in protest of the treatment of two men in isolation.
“He was ready to pay any price for the principle,” Bitton said.