Benjamin Netanyahu was sworn into office Thursday, taking the helm of the most right-wing and religiously conservative government in Israel’s history and vowing to enact policies that reflect that ideology whether the country’s allies like it or not.

Mr. Netanyahu took the oath of office moments after parliament passed a vote of confidence in his new government. His return marks his sixth term in office, continuing his more than decade-long dominance over Israeli politics.

His new government has pledged to prioritize settlement expansion in the occupied West Bank, extend massive subsidies to his ultra-Orthodox allies, and push for sweeping reform of the judicial system. The plans have sparked uproars from some sectors of Israeli society, including the military, the business community and others.

Mr. Netanyahu is the country’s longest serving prime minister, having held office from 2009 until 2021 and a stint in the 1990s. He was ousted from office last year after four deadlocked elections by a coalition of eight parties solely united in their opposition to his rule.

Despite his political comeback, he remains on trial for charges of fraud, breach of trust and accepting bribes in three corruption cases. He denies all charges against him, saying he is the victim of a witch hunt orchestrated by a hostile media, police and prosecutors.

The diverse yet fragile coalition that toppled Mr. Netanyahu collapsed in June, and Mr. Netanyahu and his nationalist and Orthodox allies secured a clear parliamentary majority in November’s election.

“I hear the constant cries of the opposition about the end of the country and democracy,” Mr. Netanyahu said after taking the podium in parliament ahead of the government’s formal swearing-in on Thursday afternoon. His speech was interrupted repeatedly by heckles and jeers from opposition leadership, who at times chanted “weak.”

“Opposition members: to lose in elections is not the end of democracy, this is the essence of democracy,” he said.

Mr. Netanyahu heads a government composed of a hard-line religious nationalist party dominated by West Bank settlers, two Orthodox parties and his nationalist Likud party.

Mr. Netanyahu’s government platform says that “the Jewish people have exclusive and indisputable rights” over the entirety of Israel and the Palestinian territories and promises to advance settlement construction in the occupied West Bank. That includes legalizing dozens of wildcat outposts and a commitment to annex the entire territory, a step that would draw heavy international opposition.

Mr. Netanyahu’s previous administrations have been strong proponents of Israel’s West Bank settlement enterprise, and that is only expected to be kicked into overdrive under the new government.

Israel captured the West Bank in 1967 along with the Gaza Strip and east Jerusalem — territories the Palestinians seek for a future state. Israel has constructed dozens of Jewish settlements that are home to around 500,000 Israelis who live alongside around 2.5 million Palestinians.

Many in the international community consider Israel’s West Bank settlements illegal and an obstacle to peace with the Palestinians. The United States already has warned the incoming government against taking steps that could further undermine hopes for an independent Palestinian state.

The White House National Security Council said on Thursday that it does not “support policies that endanger the viability of a two-state solution or contradict our mutual interests and values.”

“We support policies that advance Israel’s security and regional integration, support a two-state solution, and lead to equal measures of security, prosperity, and freedom for Israelis and Palestinians,” it added.

Earlier this week, two members of the Religious Zionism party said they would advance an amendment to the country’s anti-discrimination law that would allow businesses and doctors to avoid serving members of the country’s LGBTQ community on the basis of religious faith.

Those remarks, along with the ruling coalition’s broadly anti-LGBTQ stance, have raised fears that the new administration would jeopardize their limited rights. Mr. Netanyahu has tried to allay those concerns by pledging no harm to LGBTQ rights.

Mr. Netanyahu loyalist Amir Ohana, who is openly gay, was voted in as speaker of parliament as his partner and their two children watched from the audience. Onstage, he turned to them and promised the new government would respect everyone. “This Knesset, under the leadership of this speaker, won’t hurt them or any child or any other family, period,” he said.

Yair Lapid, the outgoing prime minister who will now reassume the title of opposition leader, told parliament that he was handing the new government “a country in excellent condition, with a strong economy, with improved defensive abilities and strong deterrence, with one of the best international standings ever.”

“Try not to destroy it. We’ll be back soon,” Mr. Lapid said.