Israel’s War in Gaza Tests Limits of Biden’s Support

Over the past two weeks, Biden has pushed Netanyahu on issues ranging from limiting civilian casualties to agreeing to a pause in fighting to free hostages. While there has been agreement in some areas, such as when Israeli commanders accepted American advice not to rush into Gaza immediately, U.S. officials are still concerned about Israel’s ultimate plans for Gaza, including any sort of extended occupation, and are alarmed by the number of Palestinian casualties.

More than 12,000 Palestinians, most of them women and children, have been killed since the current conflict started, according to health officials in the Hamas-run enclave. The figures don’t distinguish between civilians and fighters.

Although the U.S. has positioned itself publicly as providing no-strings-attached support for Israel’s right to self-defense, the scope and scale of the violence inside Gaza has given it pause.

The administration has been frustrated by Israeli settler violence targeting Palestinians in the West Bank, for example, and on Saturday, Biden sent a clear signal to the Netanyahu government that he expected it to crack down.

“I have been emphatic with Israel’s leaders that extremist violence against Palestinians in the West Bank must stop and that those committing the violence must be held accountable," he wrote in an opinion column published Saturday in the Washington Post.

He also warned that the U.S. would consider its own measures, such as banning visas for those responsible for the attacks, the first public, tangible sign that Washington’s patience with Israel was beginning to run out.

The effort to rein in Netanyahu and his hard-line government remains a continuing challenge for the Biden administration. U.S. officials have continued to shuttle between regional capitals, pressing Netanyahu and other members of his government. Those efforts have only shown mixed results thus far, and as Iranian-backed militia attacks against U.S. personnel escalate amid the hostilities, the Biden administration worries it will be drawn into a widening regional conflict.

Administration officials at the highest levels are wary of the potential domestic fallout of full-throated support to Israel and have urged Netanyahu’s government to consider that the incessant images of dead women and children may overshadow the effort to root out Hamas. It is unclear, however, whether Democratic voters would be swayed by Gaza given that the alternative might be a second Trump presidency; Republican voters remain supportive of Israel.

U.S. officials had, for weeks, pressed Israel to avoid targets that would endanger large numbers of civilians or that might raise objections for violating international law, as with recent strikes on refugee camps and hospitals. Those conversations have yielded only mixed success, and Washington has communicated its frustration with the civilian death toll to the Israeli government.

U.S. and Israeli officials say the Israelis have in recent days demonstrated the ability to conduct more precise targeting, reflecting some success in the U.S. influence campaign with Israel. Secretary of State Antony Blinken, in an interview last week with PBS, commended Israel’s efforts to limit civilian casualties but said “they can, they must, do even more."

The Israeli ground operation at Gaza’s Al-Shifa hospital, which both the U.S. and Israel say Hamas used as a command-and-control facility, reflected this moderated approach. Israel limited its operation to the ground, rather than conducting an airstrike, and brought in Arab-speaking support personnel into the hospital to help as they secured each floor.

While that approach might have reduced casualties, the United Nations says the siege of the hospital has turned the facility into a “death zone" as those inside have limited access to fuel, water and other essentials.

Israel has released video footage that it says demonstrates that Hamas was using the hospital, but it hasn’t yet shown any evidence of a suspected underground facility used by Hamas’s military wing. “I expect you’ll see more information in the coming days," Jonathan Finer, the U.S. deputy national security adviser, said in an interview Sunday on CBS’s “Meet the Press" when asked about the suspected Hamas facility at the hospital. “I think we feel confident in the information that we’ve put out."

Finer also said the U.S. wants to make sure that Israel accounts for the large number of civilians who have fled to the south of Gaza, for when Israel conducts an expected next phase of ground operations. “We think that their operations should not go forward until those people—those additional civilians—have been accounted for in their military planning," he said.

U.S. officials, including Brett McGurk, the White House’s top Middle East envoy, have also cautioned Israel against opening up a second front in the north with Hezbollah in Lebanon, which has conducted cross-border attacks. So far, those warnings appear to have been heeded.

But the Biden administration thus far has failed to persuade Netanyahu to agree to a humanitarian pause that could lead to the release of more hostages. U.S. officials said recent conversations between the two leaders have grown more strained as Netanyahu continues to resist a longer pause.

Another contentious issue has been increasing Israeli settler violence targeting Palestinians in the West Bank. Settler attacks against Palestinians in the West bank have escalated Since Hamas’s Oct. 7 assault, including one in the village of Qusra near Nablus, where three Palestinian men were killed, according to Palestinian authorities. The following day, settlers attacked the funeral, killing another two men.

U.S. and Israeli officials also could be on a collision course over what a post-Hamas Gaza looks like. While both sides agree that Israel shouldn’t occupy Gaza after the war, the Biden administration has said it wants to ensure that the enclave ultimately has a Palestinian government running it and that the territory remains intact.

Though Israel doesn’t want to administer the area, the government after the war does want to create a buffer zone inside Gaza along the border with Israel, according to several U.S. and Israeli officials. One of those officials described the buffer area as a “kill zone," or a no-man’s-land, that would remain part of Gaza, but Palestinians wouldn’t be allowed to live there.

It remains unclear how the Biden administration would regard such a proposal, since it wouldn’t technically reduce Gaza’s territory—something Blinken has specifically said the U.S. is opposed to—but it would nonetheless limit Palestinians’ access to the area.

Nancy A. Youssef and Dion Nissenbaum contributed to this article.

Write to Gordon Lubold at gordon.lubold@wsj.com and Vivian Salama at vivian.salama@wsj.com