President Biden and his senior leadership hailed Israel’s killing of Hamas leader Yahya Sinwar as an “opportunity” to end the yearlong war that has devastated the Gaza Strip and killed thousands of Palestinians.

Speaking Friday in Germany, Biden said he telephoned Israeli Prime Minister Benjamin Netanyahu and told him the elimination of the radical “terror mastermind” Sinwar meant it was time to find peace.

But is this milestone moment really an opportunity to finally enact a cease-fire? Or will Netanyahu intensify military operations and fight ahead, vindicated — in his view — that his hard-line and uncompromising offensive has proved to be the correct strategy?

“The war is not over,” Netanyahu declared triumphantly in a televised address when he confirmed Sinwar’s killing by an Israeli army unit in a building in the city of Rafah in southern Gaza.

And 24 hours later, Hamas was equally defiant. Sinwar’s “banner will not fall,” the militant organization said in a statement Friday that praised the exploits of its dead leader.

And to those who hoped Sinwar’s death might lead to the release of Israeli hostages who remain in Hamas captivity, the statement said the men and women would only be freed when Israeli troops withdraw from the Gaza Strip and Palestinian prisoners are released from Israeli jails.

It seemed likely that neither Israel nor Hamas would significantly change its battlefield operations any time soon.

Israel’s next steps will largely depend on Netanyahu’s own political calculations and those of his ultra-right coalition government, some members of which want to reoccupy Gaza and expel large numbers of Palestinians.

Sinwar’s death “gives Israel sort of the ladder to climb down from the total victory tree and say, ‘OK, we have won the war.’ We can … move toward a different reality on the ground in Gaza,” said Shira Efron, a former Rand Corp. fellow and Israel-based analyst with the Israel Policy Forum in Washington.

But it could also go the other way, she said. Netanyahu can conclude he is on a roll, Hamas is irreparably crippled, and “we should double down on fighting and continue this endless war.”

It is also difficult to predict Hamas’ next actions — defiant rhetoric aside. Much will depend on who succeeds Sinwar and what kind of game plan, if any, he left behind. Few Hamas figures today have the same popular appeal, credibility and tactical, political and strategic chops that Sinwar had.

“You now have a series of unknowns,” said Lucy Kurtzer-Ellenbogen, head of the Israeli-Palestinian program at the U.S. Institute of Peace.

Just over a year ago, Hamas-led militants invaded southern Israel, killed 1,200 people and took about 250 hostage, the deadliest single day for Jews since the Holocaust. In response, Israel launched a brutal war on Gaza that has killed more than 42,000 people, according to Gaza health officials, and destroyed around 70% of buildings and structures and displaced nearly 2 million people.

Throughout it all, the Biden administration, with allies Egypt and Qatar, engaged in tortuous talks to reach a cessation of hostilities. Israel and Hamas took turns at being the impediment to agreement, each at one time or another moving the goal post, mediators say.

Perhaps even more problematic, the negotiations often revealed a disconnect between Israel and its strongest ally in the world, Washington.

It became increasingly clear that Netanyahu and his government repeatedly ignored U.S. advice, or agreed to it but then didn’t follow through. This included entreaties to allow more food, water and medicine into a starving Gaza Strip and minimizing civilian casualties.

Bruce Hoffman, an insurgency expert at the Council on Foreign Relations, said Israel often disregarded U.S. military advice because “Israel was looking for a new status quo, not a return to the status quo ante … which I’m not sure was understood in Washington.”

The pattern continued as Israel expanded its war effort into Lebanon to confront Hezbollah, the militant and political faction in southern Lebanon that has been firing rockets into northern Israel for months. Similarly, U.S. officials called on Israel to limit its invasion into Lebanon that started Oct. 1 and then its bombardment of Beirut and other crowded population centers. Although there have been occasional pauses, Israel has not withdrawn its troops and bombings continue. More than 2,000 Lebanese have been killed.

“The conventional wisdom is that Sinwar’s death is a potential offramp for Netanyahu, but that assumes he wants one,” Khaled Elgindy, senior fellow at the Middle East Institute think tank in Washington, said in an interview. “He just doesn’t have the same calculations and intentions” as the Americans. “Trying to align American rhetoric with Israeli action has led to total contradiction.”

As much as the United States has misread Israel, both the U.S. and Israel have repeatedly misread Hamas and Palestinians.

Late Thursday, Israel released a video of Sinwar’s dying moments. He sat in an armchair in a destroyed building, covered in dust and debris, an arm apparently amputated by mortar fire. A drone moves in to observe him. He uses his last strength to shakily hurl a pole at the drone.

Israelis celebrated these images as a final humiliation to a man whom they saw as evil. But for Palestinians, the video sealed a kind of folk-hero status for the dying Hamas leader, who was seen as defiant to the end, fighting on the front lines.

Longtime observers of the Middle East say that assuming the death of Sinwar would end the war underestimates, or mischaracterizes, the goals of both Israel and Hamas.

Hamas seeks its survival as a governing force, something Israel, the U.S. and many Arab and European allies reject.

Israel’s designs for Gaza have raised concerns as it renewed large-scale attacks in northern Gaza and cut off almost all humanitarian aid into the area where Palestinians faced starvation. Some Israeli officials have voiced support for emptying the area of Palestinians as a way to form a buffer zone. The U.S. staunchly opposes such a plan.

“Ending the war has gone beyond Sinwar staying alive or not,” said Qusay Hamed, a political science professor at the Al Quds Open University in the occupied West Bank city of Ramallah.

Times staff writer Nabih Bulos in Beirut contributed to this report.