A planned visit to Washington by Israel’s top defense official was abruptly canceled by the government of Prime Minister Bibi Netanyahu on Tuesday, U.S. officials said, a sign of tensions between the two allies that casts doubt on whether the Biden administration can prevent Israel’s multifront conflict from exploding into wider war.

Defense Secretary Lloyd Austin had been scheduled to host his Israeli counterpart, Defense Minister Yoav Gallant, at the Pentagon on Wednesday for a meeting expected to focus on Israel’s expanding military operation in Lebanon and its anticipated counterstrike against Iran, whose massive missile barrage this month represented the latest salvo in a battle now spanning the Middle East.

Israeli officials have said that the country is preparing a significant military response to that attack. U.S. officials say that Israel has not briefed them on what it is planning.

Sabrina Singh, a Pentagon spokesperson, told reporters that the meeting between Austin and Gallant, who has developed a close working relationship with officials in Washington amid Israel’s year-long war against Hamas militants in Gaza, would no longer take place as planned on Wednesday. It was not clear when rescheduled talks might occur.

The last-minute cancellation underscores the complexities of the United States’ ties with its chief Middle Eastern ally since Hamas’s Oct. 7 attacks plunged the region into renewed conflict, prompting the United States to rush military assets to the region and expend considerable diplomatic effort to reach a lasting cease-fire.

According to an Israeli official, Netanyahu informed Gallant on Tuesday that he could only depart on his planned Washington visit when two conditions had been met: that a conversation between Biden and Netanyahu, which the prime minister had been expecting for several days, take place by phone; and that Israel’s security cabinet approve a military response to Iran’s missile attack.

Netanyahu has been trying unsuccessfully to reach Biden directly, said the Israeli official, who, like others, spoke on the condition of anonymity to discuss sensitive issues. Netanyahu’s office declined to comment. A U.S. official denied that Biden had rejected outreach from Netanyahu.

On Wednesday, it will be seven weeks since the two have spoken.

Friction has increased between the two leaders in the last year over Israel’s conduct of the war in Gaza, which has killed more than 40,000 people – according to local health authorities, who do not distinguish between civilians and combatants but say the majority are women and children – and over what U.S. officials see as Netanyahu’s failure to support U.S.-backed diplomatic measures and heed their advice about containing what has become a burgeoning regional conflict.

Since Iran’s ballistic missile attack, its second direct strike on Israel, U.S. officials have urged Israel to moderate any retaliatory action.

While the two countries have coordinated closely, Israel has repeatedly conducted strikes on regional adversaries without giving the United States advance notice, including a recent operation targeting Hezbollah operatives with exploding communications devices. U.S. officials have complained that such attacks may endanger U.S. troops in the region.

Biden, meanwhile, has faced criticism from within his own party for his stance on Israel and the steady supply of weapons from Washington.

While Biden and his aides have backed Israel’s right to respond to Iran, Biden has publicly urged Israel to eschew attacks on Iranian oil facilities, which could destabilize world energy markets. U.S. officials have likewise counseled Israel against striking facilities linked to Iran’s nuclear program, which Israel has long deemed an existential threat.

A U.S. official said that the administration has “been in regular consultation with the Israelis at multiple levels and have always said the leaders would talk following those consultations. That’s something we have both agreed on over the past week.”

“That said, if they’re saying we’re stiff-arming [Netanyahu] and refusing a call, that’s not true,” the official said. “In fact, we were already planning on having them speak later this week and the Israelis know that.”

The official said that in any case, “a call today wasn’t possible” since Biden was deeply involved in hurricane response efforts Tuesday and also traveled to Wisconsin and Pennsylvania.

Officials at the Pentagon had hoped that Gallant, who has spoken with Austin more than 80 times since Oct. 7, 2023, would outline Israel’s plans for a military response. It was not immediately clear whether Gallant, in lieu of in-person talks, might brief Austin by phone.

Officials at the Defense Department remain “concerned about potential escalatory action from Israel,” a senior defense official said.

If Israel were to elect to mount a direct attack on Iran’s nuclear facilities, its options would limited. Iran’s main enrichment plant near the city of Natanz is roughly 25 feet underground, reinforced with concrete. Its Fordow enrichment plant is buried inside a mountain.

Both facilities would be difficult if not impossible for Israel to destroy, according to experts. A meaningful attack on Fordow would require two elements that Israel doesn’t have – massive earth-penetrating bombs and the planes that could carry the heavy weapons to their target.

“A lot depends on geology,” said Michael Eisenstadt, director of the Military and Security Studies Program at the Washington Institute for Near East Policy. He noted that Iran has been building another facility near Natanz that is buried even deeper.

“Short of a penetration attack to destroy the interior of the underground nuclear sites, an attack could alternatively try to seal off the tunnel entrances and destroy the ventilation intakes,” said Hans Kristensen, the director of the Nuclear Information Project at the Federation of American Scientists. “But that would obviously be temporary damage that would relatively quickly be repaired.”

Israel might also launch strikes on ancillary sites, such as facilities where Iran may construct centrifuges essential for producing weapons-grade material, said James Acton, co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace. Israel might also possess a hidden capability, Acton said, such as a new type of cyberattack that could set the Iranian program back and send a message to Tehran that it’s vulnerable to unconventional warfare.

Given the difficulties of directly attacking Iran’s nuclear program, Israel may opt, at least, to establish deterrence – hitting ballistic missile sites or air defenses. A former national security official anticipated that Israel will deal a “significant blow that sends a distinct message to Tehran.”

(c) 2024, The Washington Post · Missy Ryan, Steve Hendrix, Shane Harris, Karen DeYoung