Mr. Saar realigned with the prime minister only five weeks ago, just months after he quit the government in March, when Mr. Netanyahu refused to put him on the war cabinet overseeing Israel’s strategy against Hamas in Gaza.

“This is a time in which it’s my obligation to try to contribute to decision making,” he said when he rejoined the government in September.

Opposition leaders see Mr. Saar’s shifts as evidence of his enduring pursuit for political relevance.

“Political considerations are the leading considerations for him, that’s his way,” said Benny Gantz, a former defense minister who quit the government’s war cabinet last summer and who had created a political coalition with Mr. Saar’s party, New Hope, in 2022 to oppose Mr. Netanyahu. “It is impossible to predict what he will do politically.”

Mr. Saar — who had previously served as Israel’s education, interior and justice ministers — did not respond to requests for comment on Wednesday. He is expected to start at the Foreign Ministry as soon as Thursday, his spokesman, Michael Maoz, said.

Under Mr. Saar, the Foreign Ministry will receive what the Israeli government described on Wednesday as an “unprecedented” budget increase of $145 million to improve the country’s global image with foreign media, social networks and on American college campuses.

The Israeli government said Mr. Saar would have a “permanent” role in security decisions, including policy toward Iran and its nuclear program, which Mr. Netanyahu and other senior officials have long warned threatens Israel.

Experts said Mr. Saar generally agrees with Mr. Netanyahu’s hard-line approach to Iran, the war against Hamas in Gaza and the conflict against Hezbollah.

“He is even more to the right of Netanyahu,” said Yossi Mekelberg, a senior consultant on Middle East Policy at Chatham House, a London-based research group.

He said Mr. Saar is not expected to push for an immediate cease-fire in Gaza, has not supported independent statehood for Palestinians or negotiations with the Palestinian Authority, and has called for Israeli annexation of some of the West Bank.

Still, Mr. Saar has shown he is unafraid to buck Mr. Netanyahu on high-priority issues. He opposed efforts to weaken Israel’s judiciary, which he once reportedly described as the government’s “regime coup.” He was later given some veto authority over legislation to overhaul the judiciary.

“Maybe he still is the only, or the most significant, keeper of honesty, justice, and rule of law — I give him credit for that,” said Dan Meridor, a former Israeli deputy prime minister and intelligence minister. Mr. Meridor worked with Mr. Saar when he was Israel’s education minister from 2009 to 2013.

But when it comes to foreign policy, experts agreed that Mr. Saar will likely take a backseat role to Mr. Netanyahu, who, as prime minister, will make the major decisions for Israel.

“Bibi will still be the main person who decides foreign policy,” Mr. Meridor said. “Foreign policy is very important here, and this is why I think you will still have the decision in his hands.”

Here’s a look at Mr. Trump’s policies on Israel during his first term as president.

The Abraham Accords

Under the first Trump administration, the number of Arab states that had diplomatic relations with Israel went from two to six. New agreements with Morocco, Sudan, Bahrain and the United Arab Emirates expanded a list that for decades had only been comprised of Egypt and Jordan.

The most prominent of those agreements was the Abraham Accords in 2020, which brought Bahrain and the U.A.E. into the fold — both Persian Gulf monarchies eager to shore up alliances with the West against their neighbor and longtime rival to the north, Iran.

Separate agreements with Morocco and Sudan were made weeks after the Abraham Accords were struck.

Jerusalem

Soon after he took office, Mr. Trump reversed decades of careful diplomacy when in 2017 he recognized Jerusalem as the Israeli capital of Israel and said the United States would move its embassy to the city. The embassy was relocated from Tel Aviv to Jerusalem the following year.

Israel declared West Jerusalem its capital in 1949, when the city was divided and East Jerusalem and its Arab residents were ruled by neighboring Jordan. But the position of the U.S. and most other countries had been that the city’s status should be determined through negotiations between Israel and the Palestinians, who have long wanted East Jerusalem to be the capital of a future Palestinian state.

The issue of whether to recognize Jerusalem as Israel’s capital grew more complex when Israel captured East Jerusalem in the 1967 Middle East war and subsequently annexed it. The annexation was not widely recognized by the international community.

Congress passed a law requiring the U.S. embassy to move to Jerusalem in 1995, but successive presidential administrations deferred implementing the law out of concerns it could increase instability in the Middle East.

The Golan Heights

The United States, under the first Trump administration, became the first country in the world to recognize Israel’s authority over the long-disputed Golan Heights.

In 2019, Mr. Trump signed a presidential proclamation declaring the territory part of Israel. That move was also a reversal of longstanding U.S. policy on the Golan Heights, which Israel captured from Syria during the 1967 Middle East war and subsequently annexed.

The annexation of the Golan Heights has never been recognized by the United Nations, which condemned it at the time. Mr. Trump’s decision was criticized internationally and carried primarily symbolic weight.

The population of the Golan Heights is roughly evenly divided between Israelis and Arabs who lived there before 1967.

In honor of Mr. Trump’s decision, the Israeli government planned a new settlement in the Golan that now bears his name: Trump Heights.

UNRWA

The Trump administration cut off all American funding to the United Nations agency that provides assistance to millions of Palestinian refugees, UNRWA, in 2018.

The year before, the U.S. had contributed about $360 million to the agency, which provides health care, education and other humanitarian services to stateless Palestinians.

The decision was widely denounced by world leaders. It was described at the time as political tactic to pressure Palestinian leaders to give up the right of Palestinian refugees under international law to return to property taken from their ancestors during the creation of Israel in 1948.

UNRWA has been in focus in recent months since the war in Gaza began. Israeli officials claimed that a small number of UNRWA employees were connected to the Hamas-led Oct. 7 attack on Israel last year — an assertion that prompted several countries to suspend funding and for which Israel failed to provide evidence. Last week, the Knesset passed a law banning the agency from operating in Israel.

Here is a look at the key battlegrounds in the war, which began on Oct. 7 last year when Hamas led a deadly attack on Israel, and some challenges that Mr. Katz will face.

Gaza

Israel’s military said on Wednesday that it had killed “approximately dozens” of militants in an operation in the town of Jabaliya over the previous 24 hours — part of what is effectively a re-invasion of northern Gaza aimed at preventing Hamas from re-establishing there. The military said that it had also conducted operations in the southern Gaza city of Rafah, which Israeli forces invaded in May.

Over the past year, Israel’s military has demolished Hamas’s main fighting units and, in October, they killed the group’s leader, Yahya Sinwar. But critics of the country’s military strategy argue that the fact that Israel has had to send troops back into parts of the enclave where it had previously taken control suggests that its plan to destroy Hamas entirely is flawed.

At the same time, many governments, as well as the United Nations and rights groups, have criticized the Israeli military’s strategy of bombarding Gaza, which has resulted in the deaths of more than 43,000 people, according to the Palestinian health authorities, and devastated the enclave. The toll does not distinguish between civilians and militants, though most of those identified by the health authorities are women, children and older people.

Ahron Bregman, an Israeli former military officer who is now a political scientist and expert in Middle East security issues at King’s College London, said that Mr. Katz would likely “not be keen on a cease-fire,” given the concessions that would need to be made to Hamas to enable it.

Lebanon

Israel’s military on Wednesday pounded southern Lebanon as part of an invasion that began early last month. That invasion is aimed at stopping Hezbollah, another militia group backed by Iran, from launching missiles and drones across the border.

Israel said that it had killed a Hezbollah commander who operated in the area of Khiam, southern Lebanon, and that it had carried out airstrikes that killed dozens of other militants.

Israel significantly escalated its campaign against Hezbollah in September, killing the group’s leader, Hassan Nasrallah, in an airstrike before launching the invasion. Thousands of Lebanese people have been killed in the Israeli campaign, and about a quarter of Lebanon’s population has fled their homes.

The campaign has not stopped Hezbollah from firing rockets at Israeli towns across the border. On Wednesday, sirens sounded in northern and central Israel to warn of a possible missile attack, and at least 10 projectiles crossed from Lebanon, the Israeli military said. It said that most had been intercepted or had fallen in open areas.

In his new role, Mr. Katz will need to confront questions of how deeply Israeli forces should penetrate into southern Lebanon and how long they remain there.

Lina Khatib, an associate fellow at Chatham House, a think tank in London, said that Mr. Trump’s victory “gives Israel space to increase the intensity of its military campaign in Lebanon and against Hamas.”

“Israel will try to increase the pressure as much as it can,” she added.

Iran

Senior Iranian officials said last week that their country would respond to an Oct. 26 missile attack by Israel. The scope and timing of any Iranian action, however, is unclear. The two nations have engaged in two rounds of missile strikes this year, in April and October, the first direct military confrontation after a clandestine war that lasted for decades.

West Bank

Israeli forces raided Palestinian villages in the northern part of the occupied West Bank on Tuesday, provoking clashes in which four Palestinians were killed, according to the Palestinian health authorities.

Israel has intensified its crackdown in the West Bank, which it says is a response to the rise of new militant groups, an influx of weapons smuggled into the area by Iran and an apparent increase there in support for Hamas at the expense of the more moderate Palestinian Authority. More than 700 people have also been killed in the West Bank, in part as a result of settler violence.

Ms. Khatib said that Mr. Katz would likely “double down” on the West Bank strategy.

“Netanyahu Fires Defense Minister Gallant at the Peak of a Regional War,” read the top headline on the left-leaning news outlet Haaretz’s English site, followed by a damning analysis with the headline: “Netanyahu Is a Clear and Present Danger to Israel. Now Its Defense Chiefs Face a Dire Dilemma.”

The Hebrew-language daily Maariv documented an “Outpouring of Anger” after tens of thousands of protesters took to the streets of Israel overnight and blocked traffic in Tel Aviv for hours.

Channel 13 News called it “An Act of Madness,” quoting Israel’s opposition leader, Yair Lapid.

In the Times of Israel newspaper, co-founder David Horovitz declared that “Netanyahu’s firing of Gallant mid-war is reckless, divisive and dangerous to Israel.

The conservative Israel Hayom, a widely distributed free Hebrew-language paper, disparaged the dismissal and echoed accusations from Israeli opposition leaders that it was a political move designed to secure Mr. Netanyahu’s standing with religious conservatives.

“Last night, it became official: Israel is being led by a prime minister who is a danger to state security,” columnist Yoav Limor wrote, calling the move “a stinging slap in the face to everyone who has paid the price of this terrible war.”

“They now know more than ever before that it is not the country’s security that guides the man who sends them into the battlefield, but personal and political whims,” he said.

The Israeli newspaper Yedioth Ahronoth carried the headline “Gallant’s Dismissal was Carried Out for the Sake of Haredi Parties” — a reference to political pressure from ultra-Orthodox groups to scuttle a bill that challenges their exemption from military service. Columnist Sima Kadmon likened Mr. Gallant’s dismissal to “a drone attack on the heart of the nation.”

“Is there a single sane person left who doesn’t understand what is happening here?” she wrote. “A segment of society that doesn’t serve, that shares no role in the war effort, a segment of society that shirks its responsibility and which is suffocating the reservists and their families to look out for itself—decided yesterday who would be at the helm of our military.”

Another columnist, Nahum Barnea, was more succinct.

“As of this morning you are living in a former democracy,” he wrote in the same news outlet.

“There are some democracies that die overnight, in a blood bath,” he added. “Our democracy has died slowly, gradually, softly.”

Itamar Ben-Gvir, Israel’s ultranationalist minister of national security, posted a festive “Yesssss” on social media, along with emojis of a flexed biceps muscle and the Israeli and American flags, even before the last polls had closed in Alaska.

Mr. Netanyahu himself weighed in soon after Mr. Trump’s victory speech, writing on social media, “Dear Donald and Melania Trump, Congratulations on history’s greatest comeback!”

“Your historic return to the White House offers a new beginning for America and a powerful recommitment to the great alliance between Israel and America. This is a huge victory!” the Israeli leader enthused, in a departure from the chill that has descended on his relationship with President Biden, and signing off, “In true friendship, yours, Benjamin and Sara Netanyahu.”

Mr. Netanyahu’s office described the phone conversation with Mr. Trump as “warm and cordial,” adding that the pair had “agreed to work together for Israel’s security and also discussed the Iranian threat,” without elaborating.

An overwhelming majority of Jewish Israelis view Mr. Trump as a better option for Israel’s interests than Vice President Kamala Harris. They assume that he will go easier on Israel than the Biden administration, which has widely supported Israel’s war effort in Gaza over the past year but has also criticized the humanitarian aspects of it, including the high civilian death toll.

Mr. Netanyahu may now feel emboldened by the prospect of a more amenable U.S. president as he continues to insist on total victory in Israel’s wars and engages in a high-wire exchange of blows with the country’s archenemy, Iran.

On Tuesday, Mr. Netanyahu fired his defense minister, Yoav Gallant, a main interlocutor with the Biden administration, against a backdrop of differences between the prime minister and Mr. Gallant over ending the war in Gaza and over pressing domestic issues that were threatening the stability of Mr. Netanyahu’s governing coalition.

Mr. Trump has, like the Biden administration, called for Israel to wrap up the wars in Gaza and Lebanon that were set off by the Hamas-led terrorist attack against Israel 13 months ago, but analysts say that a Trump administration would probably support ending them on terms more favorable to Israel.

That sentiment is largely based on Mr. Trump’s first term, when he bestowed political gifts on Mr. Netanyahu’s previous government, including moving the United States Embassy from Tel Aviv to Jerusalem.

But analysts also note that the policies of the next Trump administration are unknown, and that Mr. Trump is notoriously unpredictable.

“I think Netanyahu prefers the unpredictability of Trump over Harris,” said Kobi Michael, a fellow at the Misgav Institute for National Security and Zionist Strategy, a conservative-leaning Jerusalem-based research group. “But there’s a degree of wishful thinking,” he said, “because Trump can easily turn on us in seconds.”

In all his years as Israel’s longest-serving prime minister, starting from his first term in the 1990s, Mr. Netanyahu has worked with only one Republican president: Mr. Trump.

But their relationship has become more complicated. Last year, Mr. Trump publicly accused the Israeli prime minister of having let the United States down by pulling out of an operation to kill Gen. Qassem Soleimani, the leader of Iran’s Quds Force, at the last minute in 2020.

Mr. Netanyahu may have been hoping that his swift congratulatory message on Wednesday morning, before the final count was in, might erase Mr. Trump’s resentment over the congratulations Mr. Netanyahu offered President Biden last time around, after multiple news organizations had called the race but while Mr. Trump was still contesting the election result.

It is unclear how much the Republican Party’s most extreme factions will affect the foreign policy, or lack thereof, of the next administration, or how much influence the pro-Zionist Evangelist supporters of Mr. Trump will have. But in general, Mr. Trump has opposed doling out foreign aid, while Israel depends on U.S. military assistance to the tune of billions of dollars per year.

“There’s an illusion about Trump — that he doesn’t get into details or go deep, and supports Israel,” said Nachman Shai, a former minister from Israel’s center-left Labor Party. “But would Trump give $15 billion to Israel?” he said, referring to the military aid package signed by President Biden in April.

“He says ‘You get, you pay!’” Mr. Shai said of Mr. Trump. Mr. Netanyahu, he added, favors Mr. Trump “because he thinks he is less interested in foreign affairs and will bug him less about letting more food into Gaza.”

Mr. Trump has said that he wants to end wars, not start them, but he has not articulated any vision for an end game when it comes to Israel’s wars in Gaza and Lebanon, or for his approach to Iran. Alon Pinkas, a former Israeli consul general in New York, said Mr. Trump was likely to provide Mr. Netanyahu with a break from pressure to resolve the broader Israeli-Palestinian conflict, at least for a few months.

“For Netanyahu,” Mr. Pinkas said, “a president that doesn’t lean on him on the Palestinian issue is a good president.”

Beyond the natural affinity between a second Trump administration and Mr. Netanyahu’s governing coalition, the most right-wing and religiously conservative in Israeli history, many liberal Israelis also consider a second Trump term good for Israel.

“President Trump is a true friend of Israel — demonstrated through not only his words but actions,” Benny Gantz, the leader of a centrist party in the Israeli opposition, said in a statement on Wednesday. He pointed to Mr. Trump’s first tenure, when he brokered the Abraham Accords, allowing Israel to normalize diplomatic relations with several former hostile countries in the region, including the United Arab Emirates — a process the Israelis are hoping will expand.

But analysts said that a Trump administration would also be much more forgiving of any revival by the Netanyahu government of its judicial overhaul plans, which seek to curb the powers and independence of Israel’s Supreme Court and concentrate more authority in the hands of the elected government. The judicial plans deeply polarized Israel in the months before the war began and created tension with the Biden administration.

“That is probably something Trump would want to do himself, but he doesn’t need to because he already has a majority in the U.S. Supreme Court,” said Prof. Reuven Hazan, a political scientist at the Hebrew University of Jerusalem. The Trump win will make Mr. Netanyahu feel less constrained, he said, adding, “It’s his dream world, policy wise.”

Between now and Mr. Trump’s inauguration on Jan. 20, however, lie President Biden’s final months in office, a potentially perilous and challenging period for Mr. Netanyahu, since Mr. Biden will no longer be limited by electoral considerations.

A Nov. 14 deadline is looming for Israel to take specific steps to facilitate a significant increase of humanitarian aid into Gaza or risk a cutoff of U.S. military aid. The threat was laid out in a letter signed last month by Defense Secretary Lloyd J. Austin III and Secretary of State Antony J. Blinken, and addressed to Mr. Gallant and Israel’s minister of strategic affairs, Ron Dermer.

“The two-month period may decide what kind of legacy Biden wants to leave,” said Shira Efron, senior director of policy research at the Israel Policy Forum, a New York-based research group. The Trump win could lead Mr. Biden to be “more adventurous,” she added, since he will not have to worry about complicating things for Ms. Harris.

At the same time, Mr. Biden will be in his “lame duck” period, and other than possible moves against Israeli policy at the United Nations, there are probably not many measures he could do that Mr. Trump could not potentially reverse.

Yet the Trump victory may also bolster Mr. Netanyahu domestically at a time of political turmoil after Mr. Gallant’s dismissal.

“A Trump win strengthens Netanyahu politically at home, because there’s a feeling he’s on our side,” said Mazal Mualem, an Israeli political commentator for Al-Monitor, a Middle East news site, and the author of a biography of the Israeli leader, “Cracking the Netanyahu Code.”

“It gives Netanyahu a tailwind,” she added.

The departing minister, Yoav Gallant, had broken with Mr. Netanyahu by pressing for a cease-fire with Hamas, saying it was the only way to free dozens of Israeli hostages held by the group in Gaza. On the domestic front, Mr. Gallant had pushed to scrap an exemption from military service for ultra-Orthodox Jews, a measure that risked collapsing Mr. Netanyahu’s government because it angered its ultra-Orthodox members.

“Netanyahu saw Gallant as the opposition within his own coalition,” said Nadav Shtrauchler, a political analyst and former strategist for Mr. Netanyahu. “Now, it will be easier for him to go in his own direction, not just politically, but militarily and strategically.”

Mr. Netanyahu swiftly denied that he would use Mr. Gallant’s departure to fire other senior members of the security establishment. Still, commentators speculated that after replacing Mr. Gallant with Israel Katz, who is expected to be a more pliant defense minister, Mr. Netanyahu would find it easier to remove the military chief of staff, Herzi Halevi.

On a similar note, the re-election of Donald J. Trump on Wednesday may temper any backlash in Washington over Mr. Gallant’s dismissal. The Biden administration saw Mr. Gallant as a trusted partner, especially as its relations with Mr. Netanyahu soured, but the election result has further reduced its influence over the prime minister’s thinking.

“Maybe the Biden administration people didn’t like his firing, but by Jan. 20, you will have Trump,” said Itamar Rabinovich, a former Israeli ambassador to Washington. Mr. Netanyahu is “not very much concerned” by the Biden administration’s frustrations, Mr. Rabinovich said.

Still, the move still comes with potential costs for Mr. Netanyahu.

In firing the defense minister, Mr. Netanyahu has drawn accusations that he is prioritizing personal goals over national ones to appease far-right and ultra-Orthodox members of his coalition. And the move suggested that he will press ahead with policies that are either deeply unpopular, in the case of the exemption for the ultra-Orthodox, or at least polarizing — like his refusal to compromise in the cease-fire negotiations with Hamas.

Neither move will immediately bring down his government, but they could both damage him in a future election.

As Israel fights the longest war in its history, some Israelis are completing their third tours of reserve duty in Gaza or Lebanon. That has raised questions among soldiers about why they should shoulder the burden on the battlefield while Mr. Netanyahu allows ultra-Orthodox Jews to avoid military service.

The resentment over that imbalance could rise over time, even within Mr. Netanyahu’s base, much of which is conservative and religious but still serves in the military.

In a sign of widespread discontent over Mr. Netanyahu’s decision to fire Mr. Gallant, tens of thousands of protesters spilled into the streets in Israel on Tuesday night, blocking a major highway, while newspaper columnists wrote strong condemnations in the Wednesday papers.

“Netanyahu’s sacred principle, his only principle: clinging to power at any cost,” Nadav Eyal wrote in a column for Yediot Ahronot, a centrist newspaper.

“If you, the brave reservist who served 230 days this year, whose children do not sleep at night, whose businesses have suffered, whose relationships with your spouses have suffered — if you have to pay a price so that Netanyahu can close a deal with the ultra-Orthodox, you will pay,” Mr. Eyal added.

The anger has been compounded by recent allegations that Mr. Netanyahu’s office illegally obtained secret documents from the military and leaked them to foreign news outlets in order to torpedo a deal to pause the war in Gaza and free the hostages held there. Mr. Netanyahu has denied the claims and one person in his office has been arrested.

By firing Mr. Gallant, Mr. Netanyahu is “evidently calculating that it will only be a short-term firestorm and he will then be left in a better position,” said Michael Koplow, an analyst at the Israel Policy Forum, a New York-based research group.

But his support for the policies opposed by Mr. Gallant “will cost him in the long term,” Mr. Koplow said. “So even if his short term calculation is correct, he may turn out to be penny-wise and pound-foolish.”

On issues that matter most to Israel’s critics, like the conduct of Israel’s wars in Gaza and Lebanon, Mr. Gallant was fairly aligned with Mr. Netanyahu.

Prosecutors at the International Criminal Court sought arrest warrants for both men in relation to the Gaza offensive. It was Mr. Gallant who played a bigger day-to-day role in managing a campaign against Hamas that has killed tens of thousands of Gazans and damaged most of the enclave’s buildings. Mr. Gallant was also one of the first ministers to push for the killing of Hassan Nasrallah, the Hezbollah leader, months before the government signed off on his assassination.

But within Israel, Mr. Gallant was seen as a thorn in Mr. Netanyahu’s side.

His public disputes with the prime minister began several months before the war, when in March 2023 he spoke out against Mr. Netanyahu’s efforts to overhaul the judicial system. Mr. Netanyahu fired him days later, only to rescind his dismissal after mass protests swept the country.

During the war, Mr. Gallant had spoken publicly about Palestinian governance in postwar Gaza, an idea that Mr. Netanyahu had avoided discussing in detail for fear of angering far-right allies who seek to settle Jewish civilians in the territory.

And Mr. Gallant had developed a strong and independent relationship with the Biden administration, irking Mr. Netanyahu, whose relationship with President Biden has become fractious even as the president continues to arm and fund Israel’s military.

Johnatan Reiss and Gabby Sobelman contributed reporting.

Here’s more background on the ousted defense minister.

A history of clashes

After the Hamas-led attack on Israel on Oct. 7, 2023, which killed about 1,200 people and led to the abduction of 250 others, Mr. Gallant emerged as the most high-level dissident to Mr. Netanyahu within his own government.

The ousted defense minister, who was a moderate voice on security issues, had been viewed as an internal roadblock to Mr. Netanyahu’s approach to cease-fire talks. Mr. Gallant repeatedly broke with Mr. Netanyahu and urged him to reach a deal to free the remaining hostages in Gaza.

In August, the defense minister questioned the Israeli leader’s goal of “total victory” over Hamas in Gaza, calling it “nonsense.”

The defense minister also suggested that Mr. Netanyahu was letting Israel slide toward long-term military rule in Gaza — a choice that Mr. Gallant said would be disastrous.

Mr. Katz, an ally of the prime minister, is unlikely to stand in the way of Mr. Netanyahu’s approach to cease-fire talks, which critics say have undermined the possibility of a deal.

Even before the war in Gaza, Mr. Gallant had repeatedly clashed with Mr. Netanyahu over the prime minister’s hotly contested plans to weaken the country’s judicial system.

Amid widespread street protests, in March 2023, after Mr. Gallant gave a speech warning that the proposals were tearing the country apart, Mr. Netanyahu sought to fire him.

That attempted dismissal roiled the country further, prompting mass protests and a general strike. Mr. Netanyahu ultimately backed down and walked back his decision to oust Mr. Gallant.

Political and family background

Before entering politics, Mr. Gallant, 65, served as a senior general who led the Israeli military’s southern command, which oversees Gaza. In 2010, he was tapped to potentially serve as the military’s chief of staff, but the appointment never came to pass.

Mr. Gallant joined the Israel Defense Forces in 1974 and served in a commando unit before holding various leadership roles over a 35-year military career.

After leaving the military, Mr. Gallant entered politics, first with a centrist party before switching over to Mr. Netanyahu’s Likud faction. In 2022, about a dozen years after his failed bid to become chief of staff, he became defense minister in Mr. Netanyahu’s right-wing government, taking him to the apex of the Israeli security establishment

Mr. Gallant studied economics and business administration at the University of Haifa and completed a senior management program at Harvard University, according to his Ministry of Defense profile.

He lives in Moshav Amikam and is married to Claudine Gallant, with whom he has three children.

Response to Gallant’s firing

In a televised speech on Tuesday, Mr. Gallant blamed his dismissal on disagreements with Mr. Netanyahu over three issues.

Mr. Gallant said the two differed over:

• The proposed mandatory conscription of ultra-Orthodox Israelis.

• A cease-fire deal in Gaza that would secure the release of hostages held there.

• And Mr. Gallant’s insistence on an independent commission to investigate the security failures that led to the Oct. 7 attacks.

“I’ve been responsible for the security apparatus during the past two years, its successes, failures, and moments of pain,” Mr. Gallant said of his call for an investigative commission. “Only sunlight, and an investigation of the truth, would allow us to draw lessons and build our forces to face the challenges of the future.”

Late on Tuesday, large crowds of protesters opposing Mr. Netanyahu’s firing of the defense minister took to city streets. They blocked traffic and lit bonfires on a major highway in Tel Aviv.

In Jerusalem, protesters also gathered near the Mr. Netanyahu’s residence.

Johnatan Reiss contributed reporting.

Mr. Gallant, who has argued for a cease-fire deal in Gaza that would secure the release of hostages held there, said he was fired for three primary reasons: he had called for universal conscription, prioritized the return of hostages still being held in Gaza and demanded an independent commission to investigate security failures that led to the Oct. 7 attack by Hamas.

But Mr. Netanyahu has fired Mr. Gallant before — and then un-fired him — and there have been many public disagreements between the two men, who both belong to the Likud party. Here are some of the high-profile clashes between Mr. Netanyahu and Mr. Gallant that led up to today’s events.

Conscription of the ultra-Orthodox

In June, the Israeli Supreme Court ordered an end to a longstanding exemption from mandatory military service for the country’s ultra-Orthodox Jews. Mr. Gallant approved initial conscription orders for thousands of ultra-Orthodox men.

The ultra-Orthodox exemption has long polarized Israeli society, where most Jewish 18-year-olds, men and women, are conscripted for years of obligatory service. Many ultra-Orthodox view sending their children to the Israeli military as unacceptable, fearing they might be swayed by secularism or looser interpretations of religious practice.

As the ultra-Orthodox population has grown to over one million — more than 13 percent of the country — other Jewish Israelis have become increasingly frustrated and resentful of its military exemption. They say it is fundamentally unfair and untenable, especially as Israel is fighting wars on multiple fronts.

Political analysts said that the government’s internal struggle over conscription also threatened the stability of Mr. Netanyahu’s coalition, which depends on the support of two ultra-Orthodox parties that support the exemption.

Yesterday, Mr. Gallant approved the conscription of an additional 7,000 ultra-Orthodox men, adding new fuel to the dispute.

‘Total victory’ over Hamas

Mr. Netanyahu’s office publicly slammed Mr. Gallant in August after Israeli news media reported that the defense minister had disparaged the prime minister’s goal of achieving a “total victory” over Hamas in the Gaza Strip.

Mr. Gallant reportedly told lawmakers in a private security briefing that the idea was “nonsense.”

“When Gallant adopts the anti-Israel narrative, he harms the chances of reaching a hostage-release deal,” the prime minister’s office said in a statement. Victory over Hamas and the release of hostages, the statement said, is the “clear directive of Prime Minister Netanyahu and the cabinet, and it obligates everyone — including Gallant.”

In his video statement on Tuesday about dismissing Mr. Gallant, Mr. Netanyahu began by saying that his primary obligation as prime minister was to ensure Israel’s security and lead the country to “total victory,” and he again accused Mr. Gallant of playing into narratives that undermine Israel’s interests.

Postwar reckonings, for Gaza and Israel

Mr. Netanyahu’s rift with the defense minister was evident in May when Mr. Gallant, in a televised address, criticized Mr. Netanyahu’s lack of vision for a postwar Gaza.

This failure, Mr. Gallant said, was driving Israel toward two possible outcomes, both unappealing: Either Israeli would occupy Gaza militarily, or Hamas would return to power, undermining Israel’s military gains. “We will pay in blood and many victims, for no purpose, as well as a heavy economic price,” Mr. Gallant said.

The defense minister also implicitly accused Mr. Netanyahu of putting his own political survival above national interests.

In addition, Mr. Gallant and other Israeli officials have called for an investigation into the security failures that led to the Oct. 7, 2023 Hamas-led attack on Israel that ignited the current conflicts. More than a year into the war, there has been no such reckoning, which could lay blame at the feet of both the prime minister and the defense minister.

Mr. Netanyahu has said that an investigation should wait until after the war. Mr. Gallant said on Tuesday after his dismissal that “only sunlight, and an investigation of the truth, would allow us to draw lessons and build our forces to face the challenges of the future.”

Israel’s judicial overhaul

In early 2023, Mr. Netanyahu announced that he had fired Mr. Gallant — and then reversed his decision 15 days later — during a contentious clash within Israel over Mr. Netanyahu’s proposed overhaul of the judicial system to limit the power of Israel’s Supreme Court

With many military reservists vowing not to serve if the overhaul was enacted, Mr. Gallant criticized the plan and said it threatened military readiness. His dismissal spurred nationwide protests and intensified an already dramatic domestic crisis — one of the gravest in Israeli history, which many in Israel have come to believe helped to embolden Hamas to execute the Oct. 7 attacks.

The episode cemented Mr. Gallant’s reputation among some Israelis as a bulwark against the most extreme far-right elements of Mr. Netanyahu’s government, and the defense minister seemed to embrace that image throughout the war.

Announcing the decision last year to keep Mr. Gallant in his cabinet, after all, Mr. Netanyahu said: “There were disagreements between us, even serious disagreements on some issues, but I decided to leave the disagreements behind us.”

Aaron Boxerman contributed reporting

In a video statement issued by his office, Mr. Netanyahu announced the change and said Gideon Saar would replace Mr. Katz as foreign minister.

Mr. Katz’s tenure as foreign minister was defined by the regional conflict, as he sought to defend Israel against increasingly fierce and widespread global criticism for how it carried out the war, first against Hamas in Gaza and later against Hezbollah in Lebanon. Both militant groups are backed by Iran, a country which attacked and was attacked by Israel during his time as the country’s top diplomat.

After Israel barred the secretary general of the United Nations, António Guterres, from the country last month for failing to strenuously condemn an Iranian missile attack, one of the largest such barrages in history, Mr. Katz criticized him. In a statement, Mr. Katz said of the secretary general “anyone who cannot unequivocally condemn Iran’s heinous attack on Israel, as nearly all the countries of the world have done, does not deserve to set foot on Israeli soil.”

Mr. Katz previously served as foreign minister from 2019-2020 before being reappointed in early 2024 as part of a political agreement implemented before the country’s war against Hamas. He is a former member of the Israeli Parliament and has worked in other government positions such as minister of finance, transportation, energy and agriculture.

He has never held a top military position, unlike the popular Mr. Gallant, an experienced former general.

After former President Donald Trump recognized Jerusalem as Israel’s capital in 2017, Mr. Katz, then serving as a minister of transportation and intelligence, petitioned to name a train station after the American leader, “for his courageous and historic decision.”

Like the prime minister, Mr. Katz is a decades-long member of the Likud party and a supporter of the settlement movement.

Before firing Mr. Gallant on Tuesday, Mr. Netanyahu had clashed with him both over the conduct of the war and domestic issues.

The two disagreed over proposals for the future administration of Gaza and the cease-fire talks. They also disagreed over legislation supporting the overhaul of the Israeli judiciary and about the conscription of ultra-Orthodox Israelis into the country’s armed forces.

“In recent months, the trust between me and the defense minister was damaged,” Mr. Netanyahu said on Tuesday.

The military has said that Hezbollah’s munitions unit recently expanded its activities into Syria, and accused the armed group of deliberately establishing weapons infrastructure within civilian areas.

The Syrian Observatory for Human Rights, a British-based group that monitors violence in Syria, on Tuesday reported that Israeli jets struck warehouses in and near Al Qusayr, an industrial city, and that about seven explosions were heard. There were no immediate reports of casualties.

Last week, Israel said it had hit Hezbollah weapons storage facilities and command centers in Al Qusayr “to reduce the transfer of weapons from Iran through Syria to Hezbollah in Lebanon.”

On Monday, the Israeli Air Force said it had targeted a branch of Hezbollah’s intelligence headquarters in Syria. The Syrian Observatory for Human Rights reported that Israeli strike hit three farms that had previously been used as camps by members of Hezbollah and Iran’s Islamic Revolutionary Guard Corps.

Syria’s foreign ministry on Monday condemned the attacks, calling on the United Nations to act swiftly to stop the Israeli incursions, according to Syria’s state news agency SANA.

As Israel expands its war efforts in the Middle East, it appears to be intensifying its focus on Syria. On Sunday, the Israeli military said it had transferred a Syrian citizen to Israel for interrogation after a special operation in Syrian territory that took place in connection with “Iranian terror networks” near the Golan Heights.

Prime Minister Benjamin Netanyahu on Sunday said that regardless of whether a cease-fire deal could be reached with Hezbollah in Lebanon, there were several keys to achieving security along Israel’s northern border with Lebanon, including “cutting Hezbollah’s oxygen line from Iran via Syria.”

The strikes in Syria comes as the Israeli military continues its fight in Gaza, Lebanon and in the occupied West Bank. The Israeli military raided Palestinian villages in the northern part of the West Bank early Tuesday, setting off clashes with militants. Four Palestinians were killed, according to Palestinian health authorities.

It was not clear whether the dead included militants or civilians and Palestinian authorities do not differentiate in their death tolls. But the Israeli military said it had engaged in firefights during the raids that killed militants in the village of Tamoun and that it had carried out airstrikes there and near the city of Jenin.

The armed wing of Islamic Jihad, an Iranian-backed militant group, said fighters in villages south of Jenin were firing bullets at Israeli forces and detonating explosive devices.

Israel has been ramping up a crackdown in the West Bank that began before the Hamas-led Oct. 7 attacks, with authorities increasingly concerned about bolder and more sophisticated attacks by Palestinian militants. The raids have left a swath of destruction in the Israeli-occupied territory, churning up roads and leaving many civilians scared to leave their homes.

Israeli officials have said destroying the roads was necessary because of the threat of buried explosives.

Sadeq Nazzal, 60, an owner of a nursery in Qabatiya, not far from Jenin, said he heard a powerful explosion on Tuesday morning. He described a chaotic scene, with military vehicles moving along the main north-south highway and sounds of gunfire in the distance.

“We’ve become used to this situation,” he said. “But every time it happens, it upends our lives. Workplaces and schools shut down.”

During a funeral procession held in Tamoun, one of the Palestinians killed on Tuesday had been wrapped in an Islamic Jihad flag. Palestinian militant groups often drape their fallen members in flags bearing their emblems. They also will occasionally claim unaffiliated people as being among their ranks.

The raids in the West Bank suggested that Israel’s military was continuing to target armed fighters in the northern part of the territory even as it conducts major operations in Gaza and Lebanon and braces for the possibility of a wider conflict with Iran.

In northern Gaza, a deadly strike hit the town of Beit Lahia overnight, Zaher al-Waheidi, an official at the health ministry in Gaza, said on Tuesday. Israel launched a wide-scale operation in northern Gaza in October, targeting what it says is a resurgence of Hamas in the area.

The Israeli military said it struck a weapons storage facility where a militant was operating. It said it had sought to reduce the risk to civilians before the strike, without explaining what measures it had taken.

Video from the scene obtained by Reuters showed people digging through rubble around a half-collapsed building in Beit Lahia, indicating it was caused by a recent strike.

The New York Times independently verified that the scene in the Reuters video matched other imagery captured by professional photographers on Tuesday morning. Walls and concrete beams had collapsed, and a sofa appeared half buried amid the debris. In a clearing surrounded by heavily damaged buildings, four white plastic shrouds could be seen being buried at a makeshift grave.

Here’s what else is happening in the Middle East:

• Defense minister dismissal: Mr. Netanyahu fired his defense minister, Yoav Gallant, on Tuesday over differences on the prosecution of the war in Gaza and over domestic political issues. Mr. Gallant was pushing for a cease-fire deal in Gaza to secure the release of hostages, and his dismissal removes the main proponent in the government for such an agreement. The two men had also clashed over the conscription of ultra-Orthodox Israelis.

• Gaza evacuations: The World Health Organization is preparing to evacuate an expected 113 critically injured and sick Palestinians from Gaza on Wednesday in what would be one of the biggest such operations in months, according to Rik Peeperkorn, the organization’s representative for the Palestinian territories.

• Polio vaccines: The Gaza Health Ministry and U.N. aid agencies extended an emergency polio vaccination campaign in northern Gaza by an additional day, aiming to increase vaccination coverage among children under 10. The start of the second phase of the campaign had been postponed because of a lack of access and assurances about pauses in the fighting, according to U.N. agencies.

• Lebanon strikes continue: The Israeli military continued to conduct airstrikes across Lebanon on Tuesday. At least 20 people were killed and more than a dozen were wounded by an Israeli strike in the Lebanese town of Barja, a largely Sunni Muslim area outside of southern Beirut, according to Lebanon’s health ministry. Earlier in the day, one person was killed and 20 others were wounded in the nearby town of Jiyeh, a popular summer resort destination along the coast, according to the health ministry.

Rawan Sheikh Ahmad, Nick Cumming-Bruce, Nader Ibrahim and Euan Ward contributed reporting.