Three rockets are launched from the Gaza Strip, as seen from the Israeli side of the Gaza border at the southern city of Sderot on Tuesday. Heidi Levine/For The Washington Post

JERUSALEM — It was last December when the Israeli military declared victory in the Jabalya refugee camp, saying it had broken Hamas’s grip on its traditional stronghold in the northern Gaza Strip.

“Jabalya is not the Jabalya it used to be,” Brig. Gen. Itzik Cohen, commander of Division 162, said at the time, adding that “hundreds of terrorists” had been killed and 500 suspects arrested.

Five months later, Israeli forces are back in Jabalya. Ground troops are pushing into the densely packed camp, backed by artillery and airstrikes – one in a string of recent “re-clearing” operations launched by the Israel Defense Forces against Hamas, whose fighters have rapidly regrouped in areas vacated by the IDF.

Israel’s fast-moving offensive in Gaza has given way to a grinding battle of attrition, highlighting how far it remains from its chief military aim – the complete dismantling of Hamas. As an adaptable militant organization that has easy access to recruits, an expansive tunnel network and is deeply embedded in the fabric of Gaza, Hamas has shown it can weather a protracted and devastating war.

The resumption of heavy fighting in the north comes as the IDF presses ahead with its heavily criticized campaign in the southern city of Rafah – long framed by Israeli Prime Minister Benjamin Netanyahu as a final battle against Hamas’s last intact battalions. Now, American officials and some of the prime minister’s fellow cabinet members are offering increasingly blunt assessments about the resilience of the militant group and Netanyahu’s failure to plan for postwar Gaza.

In striking remarks Wednesday night, Israeli Defense Minister Yoav Gallant called on Netanyahu to make a public commitment that Israel will not end up governing Gaza after the war, amid mounting fears in the IDF that its mission is creeping toward reoccupation of the territory.

“Hamas might regain its strength as long as it maintains civilian control,” Gallant said. Failure to create an “alternative governing authority,” he said, “is equivalent to choosing between the two worst alternatives: Hamas rule or Israeli control of Gaza.”

White House national security adviser Jake Sullivan sounded a similar note on Monday: “Military pressure is necessary but not sufficient to fully defeat Hamas,” he told reporters. “If Israel’s efforts are not accompanied by a political plan for the future of Gaza, and the Palestinian people, the terrorists will keep coming back.”

Palestinians walk through the debris after an Israeli air and ground offensive Wednesday in Khan Younis, southern Gaza Strip. Saher Alghorra/Associated Press

Netanyahu said last week that Israel has killed 14,000 Hamas militants; the IDF put its estimate at 13,000 last month. The numbers are not possible to independently verify – and no evidence has been offered to support them – but even the high-end figure would amount to less than half of Hamas’s estimated fighting force before the war. Thousands of other militants belong to smaller groups that vie with Hamas for local influence.

More than 35,000 Palestinians have been killed since October, according to the Gaza Health Ministry, which does not distinguish between civilians and combatants but says the majority of the dead are women and children. Health services have been decimated, many families have been displaced multiple times, and a “full-blown famine” has taken hold in the north, according to the head of the World Food Program.

“It would be astounding for me if it wasn’t incredibly easy for Hamas and other militant groups in Gaza to recruit,” said H.A. Hellyer, a scholar specializing in Middle East security at the Carnegie Endowment for International Peace and the Royal United Services Institute.

While Hamas has been “significantly and substantially degraded,” he said, an organization that has been active in Gaza since the 1980s and governed it for more than 15 years is not going to “simply disappear.”

After seven months of bombardment and ground operations by one of the world’s “most powerful armies,” he said, “Israeli forces still haven’t been able to come close to victory.”

When Israeli troops withdrew from Jabalya last year, Hamas began a recruitment drive for jobs securing aid and setting up a new headquarters there, according to residents. “There is the presence of policemen, but without a police uniform, and they are all in civilian clothes,” said a 42-year-old Jabalya resident, speaking on the condition of anonymity out of fear for his safety.

Israel says four Hamas battalions remain intact in Rafah, where its troops are slowly approaching residential areas despite threats by President Biden to cut off military aid.

There are several “layers” of Hamas fighters embedded in the city, said Maj. Gen. Tamir Hayman, a former head of Israeli military intelligence. He said the operation would focus on “the people who are underground, underneath military installations, and others who are above ground, and connected to the underground layer,” waiting to “carry out ambushes” on Israeli troops.

Two hundred and seventy-three Israeli soldiers have been killed in Gaza since the beginning of ground operations in October, following Hamas’s deadly attack on southern Israel. Though rocket barrages from the enclave subsided for months after Israel’s campaign in the north, they have been ramping up again in recent weeks.

On Tuesday, a rocket could be seen streaking toward the Israeli border town of Sderot, a vivid reminder of Hamas’s staying power. Israeli military helicopters swooped in for medical evacuations. The injured were rushed to waiting ambulances.

Israel Ziv, a retired major general who served as the head of the IDF Operations Division, said the country looks set on continuing “a multi-chapter war” that could unfold like the one it waged in southern Lebanon starting in the 1980s – which involved devastating bouts of fighting and a 15-year occupation, but ultimately failed to eliminate the threat of Hezbollah.

Ziv estimated there are at least 20,000 Hamas militants left in Gaza who “will easily recruit the next 40,000.”

Earlier gains by the IDF have “evaporated” because of a lack of political plans, he said. “If you are working only militarily without any diplomatic solution, you’re inside this swamp. Israel is stuck inside Gaza.”

Netanyahu has resisted U.S. proposals for the Palestinian Authority to play a leading role in postwar Gaza, or to consider a path to a Palestinian state, arguing that it would reward Hamas for their Oct. 7 atrocities.

Experts say his refusal to address the heart of the Israel-Palestinian conflict is stymieing buy-in from Arab states in planning for postwar security.

“Who is going to want to come in, govern and essentially be the police for the Israeli occupation?” Hellyer said. “Israel is blocking off any and all avenues that look sensible.”

As long as Hamas retains its military grip on Gaza, it is clear that “no entity will be willing to take on the civil administration of Gaza for fear of its safety,” Netanyahu said in a statement Wednesday. “Therefore, discussions about ‘the day after,’ while Hamas remains, will remain just empty talk.”

But frustrations are growing within the Israeli military, and generals are speaking more freely about the deepening security vacuum.

“There is no doubt that creating an alternative to Hamas would put pressure on it,” Israeli military spokesman Rear Adm. Daniel Hagari said at a news conference Tuesday when asked about Hamas’s return to the north. “But that is a question for the political leadership,” he added pointedly.

Former prime minister Naftali Bennett likened the state of the war to “mopping water up a slanted floor.”

“Somehow planning for post-Hamas Gaza has become a taboo in our government,” he wrote on X this week. “We can decide to keep Israeli temporary admin, or local Palestinian, or other options. But we need to decide SOMETHING. Who fills the void.”

Military experts warn that Israel could be lurching toward a new military occupation – a nightmare scenario for the IDF and another possible fault line in relations with Washington, where officials have insisted that “Gaza is Palestinian land and will remain Palestinian land.”

Speaking in October, Gallant listed “the removal of Israel’s responsibility for life in the Gaza Strip” as one of the main aims of the war. Seven months on, that appears a distant possibility.

“Unfortunately, we haven’t taken care of the replacement of Hamas,” said Kobi Michael, an expert at Israel’s Institute for National Security Studies. “The only option I can see is a temporary military administration that will take care and run the territory and the population and the humanitarian aid,” he said, noting that the idea was now being discussed more seriously in Israel’s military establishment.

Netanyahu’s recent public statements also suggested a long-term Israeli military presence in Gaza. “If you look at what you need to do after this war is won, you’ll have to have sustained demilitarization by Israel,” he said in a podcast interview this week. “If you have to be inside, you be inside.”

Yossi Melman, a longtime intelligence columnist for the Haaretz newspaper, said the IDF mission has lost its compass.

“They are like zombies wandering around,” he said. “They don’t know what to do.”