Live Updates: Netanyahu Offers Full-Throated Defense of Gaza War

“My friends, if you remember one thing, one thing from this speech, remember this,” Mr. Netanyahu said. “Our enemies are your enemies. Our fight is your fight. And our victory will be your victory.”

He also lavished praise on both President Biden and former President Donald J. Trump. He largely avoided talking about differences of opinion between himself and President Biden and instead directed anger at antiwar protesters, whom he accused of sympathizing with terrorists and acting as “Iran’s useful idiots.”

He did not mention a cease-fire by name, or discuss the status of the deal that Israel and Hamas have been negotiating for weeks and that the Biden administration desperately wants to get done. He did say that the war could end if Hamas surrendered, disarmed and returned hostages.

Mr. Netanyahu received repeated applause from Republican senators and representatives seated in the House chamber for the joint meeting, which dozens of Democratic lawmakers declined to attend, including two top senators and Representative Nancy Pelosi, the former House speaker.

Vice President Kamala Harris declined to preside over the session, as is traditional for the vice president, citing a scheduling conflict. Nearly 100 House and Senate interns called in sick to protest the speech.

Mr. Netanyahu laid out a vision for the day after the war ends, saying that after Israel defeats Hamas “a new Gaza could emerge,” and that Israel had no plans to “resettle” Gaza. That is an issue that Ms. Harris — now the presumptive Democratic presidential nominee — has been pressing since the war began.

Outside the Capitol, more than 5,000 pro-Palestinian demonstrators gathered to protest the speech, some wearing Palestinian scarves, chanting for the United States to stop arming Israel. Some carried signs calling Mr. Netanyahu a “war criminal” and the “prime minister of genocide.”

Here’s what to know:

• In Gaza: The death toll since the war began more than nine months ago has surpassed 39,000, according to the health authorities in the enclave, whose numbers do not distinguish between civilians and combatants. Israel has been attacking areas of eastern Khan Younis, a city in southern Gaza, that it had previously designated as a humanitarian zone, saying that militants were firing rockets and Hamas was attempting to regroup there. More than 270 aid workers have been killed during the war, according to the United Nations.

• Cease-fire talks: While both sides have agreed to the broad outlines of a three-phase cease-fire deal, negotiations to end the war in Gaza and free the hostages appear to have reached a standstill. On Thursday, a delegation of Israeli negotiators is expected to meet with mediators abroad, according to Mr. Netanyahu’s office, but it is not clear where the meetings will be held or how high-level they will be. Israel says it will only agree to a permanent cease-fire after Hamas’s elimination and the return of the 120 living and dead hostages in Gaza. Hamas has said it will not return any of the hostages unless Israel provides a path to a permanent cease-fire. At the same time, Hamas has resisted calls to abandon its control of the Gaza Strip, which it has ruled since 2007.

• Meeting candidates: Mr. Netanyahu will meet with Ms. Harris in Washington on Thursday, after a separate meeting with President Biden. The two men will also meet with family members of Americans held hostage by Hamas, the White House said. The Israeli leader will then travel to Florida to meet with former President Donald J. Trump at his private club, Mar-a-Lago, on Friday. The Israeli leader was invited to Washington weeks ago, before Mr. Biden’s decision not to seek re-election. The relationship between Mr. Biden and Mr. Netanyahu has grown testier in recent months as the war has dragged on.

At least two family members of Israeli hostages were arrested by Capitol Police during Netanyahu’s speech to Congress, according to groups representing the families. One, Carmit Katzir, was removed from the gallery while wearing a yellow T-shirt that called for Netanyahu to immediately “seal the deal” for the hostages’ release, the Hostages and Missing Families Forum confirmed.

Katzir’s father was killed during the Oct. 7 attacks and her mother and brother were taken hostage, according to the Israeli military. While her mother was released as part of a brief cease-fire deal in November, the Israeli military said her brother was killed in captivity in January. “He could have been saved if there had been a deal in time,” Katzir said when his body was later recovered. “But our leadership are cowards.”

“When we fight Iran, we are fighting the most radical and dangerous” opponent of America, Mr. Netanyahu said, adding, “We are not only protecting ourselves, we are protecting you.”

Ever since the 1979 revolution that made Iran a Shiite Muslim theocracy, the country has been isolated and has seen itself as besieged. Iran considers the United States and Israel its biggest enemies, and its leaders have long vowed to destroy Israel. It also wants to establish itself as the most powerful nation in the Persian Gulf region, where its chief rival is Saudi Arabia, an American ally.

For the United States and its allies, concerns about Iran are often focused on the risk that it could develop a nuclear weapon. But for Israel, the threat is much more immediate, with Iran using proxies in other countries to strike Israeli interests.

Here are some ways that Iran has clashed with Israel.

Through Hamas: This Palestinian group has received weapons and training from Iran and has fought repeated wars with Israel. Iranian officials have publicly denied being involved in or ordering Hamas’s Oct. 7 attack on Israel that killed about 1,200 people. But they also praised the assault as a momentous achievement and warned that their regional network would open multiple fronts against Israel if the country kept up its retaliatory war against Hamas in Gaza.

Through Hezbollah: A Lebanon-based militia that is widely considered to be the most powerful and sophisticated of the Iran-allied forces, Hezbollah was founded in the 1980s with Iranian assistance, specifically to fight the Israeli occupation of southern Lebanon. The group, which is also a political party in Lebanon, has fought multiple wars and border skirmishes with Israel.

Hezbollah has been trading fire across the border with Israel’s military almost daily since the Oct. 7 attack, and the risk of all-out war is higher than ever. A cease-fire in Gaza could reduce that threat.

Through the Houthis: The Houthi movement in Yemen launched an insurgency against the government two decades ago. What was once a ragtag rebel force gained power thanks at least in part to covert military aid from Iran, according to American and Middle Eastern officials and analysts.

Since the war in Gaza began, the Houthis have waged what they call a campaign in solidarity with Palestinians. They have disrupted a significant part of the world’s shipping by attacking vessels heading to or from the Suez Canal and have launched missiles and drones at Israel, including a drone that hit an apartment building in Tel Aviv last week, killing one person. Israel hit a Yemeni port in retaliation.

Direct attacks: Israel has long carried out targeted assassinations of Iranian military leaders and nuclear scientists, but in April it took the bold step of killing several high-ranking Iranian officials in a strike on an Iranian government building in Syria.

Senior Israeli officials believed that such a brazen assault would act as a deterrent against Iran. Instead, the attack achieved the opposite, prompting Iran to target Israel with one of the largest barrages of ballistic missiles and drones in military history and turning what had been a shadow war into a more open conflict. Israel responded with a more limited strike.

Israel says it will only agree to a permanent cease-fire after Hamas’s elimination and the return of the 120 living and dead hostages in Gaza. Hamas has said it will not return any of the hostages unless Israel provides a path to a permanent cease-fire. At the same time, Hamas has resisted calls to abandon its control of the Gaza Strip, which it has ruled since 2007.

On Thursday, a delegation of Israeli negotiators is expected to meet with mediators abroad, according to the prime minister’s office. It was not clear where the meetings would be held or how high-level they would be.

Both sides have agreed to the broad outlines of a three-phase cease-fire deal. It would begin with a six-week truce, during which some hostages would be released in exchange for Palestinian prisoners held in Israeli jails. Israel and Hamas would then negotiate over terms for a permanent cease-fire and the withdrawal of Israeli forces in the second and third stages.

That framework has been backed by President Biden and broadly endorsed by the United Nations. Israel’s government also privately greenlit the proposal, although Mr. Netanyahu took weeks to publicly and unequivocally endorse it.

Analysts say that Mr. Netanyahu has sought to buy time, balancing competing demands at home and abroad while avoiding tough decisions that would jeopardize his political standing.

The end of the war would most likely revive a national reckoning over Mr. Netanyahu’s failure to prevent the Hamas-led surprise attack on Oct. 7 that set off the war. And it could topple his government: His hard-right coalition partners have vowed to oppose any deal that would effectively leave Hamas in power in Gaza.

Earlier this month, Hamas submitted its latest counteroffer on the deal framework. U.S. and Israeli officials said Hamas had made some concessions, allowing the talks to move forward. But despite meetings involving Israel, the United States and the regional mediators Egypt and Qatar, there has been little reported progress.

At the same time, Mr. Netanyahu has publicized a new list of conditions for a deal. Israel must be allowed to continue fighting against Hamas should it choose to do so, he said, and it will not allow “thousands of armed terrorists” to return to northern Gaza.

Israeli officials have also demanded guarantees to ensure that Hamas cannot rearm itself by smuggling weapons into Gaza from Egypt. Israel and Egypt have discussed proposals including installing electronic sensors that could detect efforts to dig tunnels under the border, as well as constructing underground barriers to block tunnel construction.

In a statement, one organizer with the group, Congressional Staff for a Ceasefire Now, who identified himself only as Ishmael and a Palestinian American, listed its demands: “Stop funding this war against civilians. Send meals, not missiles. Secure the release of Israeli hostages and arbitrarily detained Palestinians. And use the leverage the American people have paid for to establish a lasting cease-fire that will bring an end to this brutal war.”

The staff members, wearing business suits and dresses, unfurled a banner with the phrase, “Staff say kick the war criminal out of our Capitol!”

The walkout was the latest in a series of high-profile yet fully anonymous actions that congressional aides have taken in recent months to publicly urge members of Congress — their own bosses — to call for a cease-fire in Gaza and halt shipments of U.S.-made weapons to Israel.

As part of a vigil last November, more than 100 staff members covered the Capitol steps with nearly 10,000 carnations to represent each life lost in the Israel-Hamas war up to that point. More than 38,000 people have been killed in Gaza during the Israeli military campaign, according to the Gazan Health Ministry.

Earlier this month, the Congressional Progressive Staff Association urged lawmakers to protest or boycott Mr. Netanyahu’s speech. They circulated a letter supported by 230 House and Senate aides, who declined to give their names, from across 122 Democratic and Republican congressional offices.

Congressional aides who have broken with their bosses on the situation in Gaza have almost all done so anonymously, fearful of losing their jobs or being penalized for publicly taking a stance at odds with the member of Congress they serve — an action considered egregious on Capitol Hill.

Also on Wednesday, a group of nearly 100 House and Senate interns called in sick to protest Mr. Netanyahu’s speech. In a statement, the interns called on their bosses to boycott the address.

“We urge our representatives to respond to the collective will of the American people and reject any semblance of endorsement for Netanyahu’s actions.”

The bell outside Union Station bears graffiti protesting the war, and demonstrators raised the Palestinian flag atop a flagpole outside the station.

Protesters have set an effigy of Netanyahu on fire outside the station. There is black smoke rising and filling the area.