At the end of a war in Gaza in 2021, Yahya Sinwar, the leader of Hamas, was photographed sitting in an armchair in his ruined home, a symbol of continuing resistance to Israel.
Mr. Sinwar was killed in this latest Gaza war, in which Benjamin Netanyahu, the prime minister of Israel, vowed to dismantle and destroy Hamas. And yet, as a cease-fire took hold on Sunday after 15 months of massive destruction and death, Hamas — badly wounded and diminished — has survived and, at least for now, will remain in charge in Gaza.
Thousands of Hamas fighters have already re-emerged from hiding and fanned out to reestablish control.
“In blunt terms, Hamas are not only still standing, but they remain the most significant force in Gaza,” said Daniel Levy, a former Israeli negotiator and president of the U.S./Middle East Project, a research organization based in London and New York.
The situation underlines the fragility of a deal reached with Mr. Netanyahu, who is facing tremendous political pressure at home. It also comes as Donald J. Trump is set to become president again amid great uncertainty over how he plans to deal with a landscape in the Middle East that is much altered since his first term.
And the war is not over. The three-phase cease-fire deal, largely unchanged from a plan President Biden announced eight months ago, is extremely fragile, as evidenced by the tension-filled delay in starting it on Sunday morning. There will be 16 days before talks are expected to begin on the second phase.
Getting from this first phase to the second, which would really mark the effective end of the war, with the nearly complete withdrawal from Gaza of Israeli troops, is considered by many to be enormously difficult, even improbable, given the concessions required and the political dynamics on both sides.
Mr. Trump was credited by many for demanding that Mr. Netanyahu do this deal now, providing the Israeli prime minister with the cover to do so. Whether Mr. Trump and his team, with so much else on their plate, will spend the time and leverage to push through the next, most fraught phase remains unknowable.
Mr. Trump is not going to want fighting to resume on his watch, said Natan Sachs, director of the Center for Middle East Policy at the Brookings Institution, a Washington research institute. But Mr. Netanyahu, faced with strong opposition to the deal within his own coalition, “does not want to end the war, and Hamas, too, intends to continue its military struggle and rearm,” Mr. Sachs said.
Mr. Netanyahu is likely to search for any Hamas violation of the terms of the truce as “justification for why phase two can’t and won’t happen,” said Sanam Vakil, director of the Middle East and North Africa Program at Chatham House, a research institute in London. “And he’ll play real hardball about the conditions of the Israeli withdrawal.”
The deal may end the fighting for now, but as in Lebanon, it gives Israel and its military “the perpetual freedom to act,” Ms. Vakil said, referring to the cease-fire signed in November with Hezbollah, the Lebanon-based militia. Mr. Netanyahu himself said on Saturday, in a speech to the nation, that Israel “reserves the right to resume the fighting if Israel reaches the conclusion that negotiations over stage two are hopeless.”
Mr. Netanyahu has consistently refused to discuss who or what will govern Gaza instead of Hamas, essentially ceding the territory to the group Israel has spent the last 15 months trying to destroy, killing tens of thousands of people, both civilians and combatants, in the process. The war erupted after Hamas led attacks on Israel on Oct. 7, 2023, killing about 1,200 people and capturing about 250 others.
Now back in control in Gaza, Hamas will be effectively in charge of a massive influx of humanitarian aid. Yahya Sinwar’s brother, Muhammad, now runs Hamas in Gaza.
Mr. Trump, too, is going to face a complicated and knotty choice about how much to invest his authority in the Middle East, especially if he wants, as he says he does, to revive plans for the normalization of relations between Saudi Arabia and Israel. A deal between the two countries had seemed on the verge of happening before the war erupted in Gaza.
Mustafa Barghouti, a member of the Palestinian Legislative Council, said the cease-fire deal was good for the Palestinians — “the killing will stop and prisoners will get out of jail” and there would be a surge of humanitarian aid. But there were no guarantees the deal would hold, he said, adding that Palestinians “need a true process that leads to the end of the Israeli occupation” of both Gaza and the West Bank.
The Saudis have made it clear during the war that they now demand concrete steps on the path toward an independent Palestinian state, which Mr. Netanyahu has repeatedly vowed to prevent. And some of those around Mr. Trump favor a further or even complete Israeli annexation of the West Bank, which could make a viable Palestinian state almost impossible. His nominee for ambassador to Israel, Mike Huckabee, said during a visit to Israel in 2017 that there “was no such thing” as a West Bank or occupation.
“Annexation of the West Bank would kill any chances for a two-state solution,” Mr. Barghouti said.
At some point, said Aaron David Miller, a former American diplomat now with the Carnegie Endowment, “Netanyahu is going to come into conflict with Trump, who wants a deal with the Saudis and Iran.”
Even the Gaza deal presents a serious domestic political challenge for Mr. Netanyahu. Already, one of the far-right parties in his coalition, led by Itamar Ben-Gvir, has quit, vowing only to return if the war restarts. If the coalition’s other far-right party, led by Israel’s finance minister, Bezalel Smotrich, also defects, Mr. Netanyahu would be leading a minority government nearly two years before the next election.
In addition to Gaza, Mr. Netanyahu also faces two thorny domestic issues, a new budget and a bill over conscripting the haredim, or ultra-Orthodox, ensuring conflict with the far right and the religious parties. The budget is vital. If it is not passed by the end of March, Mr. Sachs said, the governing coalition is automatically dissolved.
“There could be a real political crisis, so we may see Trump versus Ben-Gvir and Smotrich as we approach phase two,” Mr. Sachs said.
Those political considerations could come to a head if Mr. Trump decides to push for a deal with Saudi Arabia — and present Mr. Netanyahu with a difficult choice.
The Israeli leader could cede to his coalition partners, hold back a deal and likely anger his most important ally, the United States. Or he could dissolve the government and call for elections based on working with Mr. Trump for a more lasting regional peace — including real steps toward a Palestinian state.
That final option would present a considerable risk for Mr. Netanyahu, whose unpopularity among centrist voters forced him to join up with Mr. Ben-Gvir and Mr. Smotrich in the last election.
Hanging over everything is Iran, which is enriching uranium to the edge of weapons grade at a rapid pace. Iran denies it is aiming for a bomb, but it is badly diminished regionally and its economy is tanking. Both Israel and the United States have vowed to prevent any Iranian nuclear bomb, and there is a strong argument inside Israel that now is the time to strike Iran.
But Mr. Trump is thought unlikely to want to get dragged into another war, and he is said to be open to a bargain with a weakened Iran. The president of Iran, Masoud Pezeshkian, has been reaching out to European diplomats and Trump officials to say his country also wants a deal on its nuclear program in exchange for lifting punishing economic sanctions.
Mr. Trump is essentially unpredictable, said Mr. Sachs. Mr. Netanyahu and the Israelis, he said, “will face a U.S. president who will certainly be very pro-Israeli — and whose favor they are keen to receive — but who will also be forceful in demanding whatever he thinks is in his interest.”