Tensions related to security needs and internal Israeli turmoil came to a sharp focus Wednesday after the American secretary of defense, Lloyd Austin, was forced to cut short a visit to Israel to discuss the growing Iranian threat. 

As part of a Mideast swing that took the Pentagon chief to Jordan and Egypt and included a previously unannounced visit to Iraq, Mr. Austin was scheduled to arrive in Israel Wednesday night and conduct a full day of meetings the next day. Instead, he was diverted back to Amman, and is now expected to confer quickly with Prime Minister Netayahu and the defense minister, Yoav Galant, near Ben Gurion airport and then fly home Thursday. 

The Israel visit was initially planned as the last, and perhaps most crucial, stop in a Mideast swing chiefly meant to focus on Iran’s nuclear race and the Islamic Republic’s tightening relations with an American foe, Russia. The Israel leg was shortened by a burgeoning protest movement against the prime minister’s proposed changes to the judiciary. Anti-Netanyahu protesters are planning a “day of resistance” on Thursday that is to include the blocking of major traffic arteries. 

The site of the country’s largest weekly protest, Tel Aviv’s Kaplan Street, is adjacent to Hakirya, the Israeli equivalent of the Pentagon, where Mr. Austin planned to conduct a day of meetings with Israel’s top security officials. On top of that, Mr. Netanyahu is scheduled to fly to Italy Thursday night for a meeting with Prime Minister Meloni, and protest organizers plan to block access to the airport. 

Facing a major logistical headache, Israeli officials requested a change in Mr. Austin’s itinerary, the Financial Times reported. The meeting will be conducted on Thursday at the Israeli Aerospace Industries’ headquarters next to Ben Gurion airport. To avoid getting stuck in protest, Mr. Netanyahu will make the short trip there in a helicopter. 

The drama surrounding Mr. Austin’s change of plans overshadows what could be part of a major shift in America’s Mideast policies. As Iran diplomacy fizzles, an alternative course correction is much needed if President Biden is to fulfill his vow to prevent the Islamic Republic from acquiring nuclear weapons under his watch.  

The International Atomic Energy Agency recently discovered uranium enriched to just below weapon-grade 90 percent purity in Iran. The Pentagon’s Colin Kahl testified this week that Tehran is a mere 12 days away from amassing enough fissile material for a nuclear bomb. At the same time, Iran is selling Russia attack drones to use in Ukraine and is asking the Kremlin for advanced anti-aircraft S-400 missiles, which could complicate any attack plans against its facilities.

For America and Israel, “the need for a plan B on Iran is growing,” a vice president for research at the Foundation for Defense of Democracy, Jonathan Schanzer, says. If Washington is contemplating a more muscular response than before, Israel, which has long advocated for military action, needs to play a major part in it. 

Regardless of the last-minute complications, “it’s good that Austin is still going at a time that the Israelis should be very happy to hear from him,” Mr. Schanzer tells the Sun. On the secretary’s agenda, he adds, “Iran is front and center” — ahead of coordination among America’s Mideast allies and of calls for reduction in West Bank and Gaza violence. 

Mr. Austin’s visit follows tours of the country by Secretary Blinken and the national security adviser, Jacob Sullivan. The largest ever joint Israeli-American military exercise was conducted recently as well. The Israeli national security adviser, Tzachi Hanegbi, and the country’s minister of strategic affairs, Ron Dermer, are at Washington for meetings with top administration officials.

The two officials and Mr. Sullivan “pledged to enhance coordination on measures to prevent Iran from acquiring nuclear weapons and to further deter Iran’s hostile regional activities,” according to the White House. 

Republican critics, however, see red behind such statements. On Monday the Washington Free Beacon reported on the Department of State’s $38,000 funding of an Israeli group, the Movement for Quality Government, which is part of the anti-Netanyahu protest. Senator Cotton followed up with a press release accusing Mr. Biden of “treating Prime Minister Netanyahu like he’s a rival or even an adversary,” rather than an ally. 

The almost unprecedented state of division in Israel, meanwhile, is threatening its most cherished institution: the military. In solidarity with the anti-government protest, 37 pilots in an air force reserve unit that would be used to take part in an attack on Iran’s nuclear facilities announced this week that they would boycott a periodic exercise.

The pilots eventually showed up, but their act raised questions about the movement — as well as about Mr. Netanyahu’s wisdom in promoting judicial reform at a time when the Iranian situation is so critical and with an uptick in Palestinian violence as Ramadan and Passover approach. 

“Israel was born in crisis and remains in crisis, yet there have been times in the past, and maybe in the future, when things were quieter,” Mr. Schanzer said. “Is this the right moment to engage in this debate?”

Mr. Biden, similarly, must decide whether he wants to interfere in an internal debate over the nature of another country’s democracy, or instead concentrate on helping Mr. Netanyahu to deal with an Iran situation that is dangerous to both countries.