Israel and Hamas reached an agreement on an initial six-week truce in part by putting off their most intractable disputes to a nebulous second phase — which neither side is sure they will reach.
Under the agreement, 16 days into the initial cease-fire, Israeli and Hamas officials are expected to begin negotiating next steps: an end to the war, the release of the remaining living hostages from Gaza and the withdrawal of Israeli forces from the territory.
Israeli leaders have long insisted that they will not end the war until Hamas is destroyed. That appeared far from reality on Sunday as Hamas militants, some waving rifles, fanned out in parts of Gaza in pickup trucks, in a show of authority to Palestinians and Israelis alike.
Israel and Hamas have both preserved some of their bargaining chips. At the end of the 42-day truce, Hamas will still have around two-thirds of the 98 remaining hostages, including dozens who are believed to be dead. And Israel will still occupy parts of Gaza, and hold major prisoners, including Marwan Barghouti, a militant leader and iconic Palestinian political figure.
But as part of the talks, the Israeli government will then probably have to decide whether it is willing to choose one of its war aims, bringing home the hostages, over another, destroying Hamas. And choosing the hostages might threaten Prime Minister Benjamin Netanyahu’s grip on power in Israel.
In the meantime, both sides have agreed to postpone a decisive agreement as to the war’s end and the future of Gaza, and hope the 42-day cease-fire will play to their advantage, said Shlomo Brom, a retired Israeli brigadier general. Hamas, in particular, “hopes that the new dynamic will prevent Israel from returning to fighting,” he said.
The decision to accept a temporary cease-fire opened deep fissures within Mr. Netanyahu’s governing coalition, which is stacked with hard-liners. Itamar Ben-Gvir, the far-right national security minister, resigned in protest from the cabinet and withdrew his Jewish Power party from the coalition on Sunday.
The Religious Zionism party, led by Bezalel Smotrich, threatened to bolt the coalition, too, if Mr. Netanyahu failed to renew the fighting after the end of the 42-day truce. If Mr. Smotrich’s party also left, Mr. Netanyahu’s government would hold fewer than half of the seats in the Knesset, Israel’s Parliament, which could cause the government to fall and force new elections.
On Saturday night, Mr. Netanyahu stressed that the cease-fire was temporary for now. He argued that Israel retained the right to return to the war if “the second stage negotiations are ineffectual,” adding that President-elect Donald J. Trump would support Israel’s decision.
“We retain the right to return to the war, if necessary, with the backing of the United States,” Mr. Netanyahu said in a televised address.
The truce’s fragility was underscored on Sunday morning when Hamas did not immediately hand over a list of hostages to be released to Israel, prompting a nearly three-hour delay in the cease-fire. Analysts say the deal will probably see numerous similar tests over the next few weeks as both sides flex their muscles.
The families of Israeli hostages still held in Gaza have called on the Israeli government to bring home the remaining captives by fulfilling all the phases of the deal. Noa Argamani, a freed hostage whose boyfriend, Avinatan Or, remains in captivity, said that it broke her heart that he was not going to be freed in this round.
“The progress in the past few days is a very important step, but the deal must go through in full, completely, in all of its stages,” Ms. Argamani said in a speech in Miami on Thursday.
