By David Ignatius

With little public fanfare, the United States and Israel this week staged a massive military exercise in the Mediterranean clearly meant to simulate a strike against Iran. It was a reminder that no matter what else is happening in the world, the poisonous kettle of the Iranian nuclear program keeps bubbling.

“Juniper Oak 23,” as it was dubbed, was the largest joint U.S.-Israeli military exercise ever, according to Brig. Gen. Patrick Ryder, a Pentagon spokesman. What caught my attention was that it involved all the weapons systems that would be needed for a U.S.-Israeli assault against Iran’s nuclear facilities.

The simulated operations included “electronic attack, suppression of enemy air defenses, strike coordination and reconnaissance, and air interdiction,” which are “exactly what the United States and Israel would need to conduct a successful kinetic attack on Iran’s nuclear program,” wrote Bradley Bowman and Ryan Brobst, two analysts with the pro-Israel Foundation for Defense of Democracies. They noted that the exercise included “three successive waves of attacks” by B-52 bombers.

The Biden administration would doubtless rather focus publicly on other military issues, starting with the war in Ukraine and the “pacing threat” posed by an increasingly powerful China. But Iran is a problem that doesn’t go away, even as three successive American presidents have tried to reduce U.S. military involvement in the Middle East.

The joint show of force is a boon for Benjamin Netanyahu, newly elected again as Israeli prime minister. Israeli media showed him Wednesday intently watching video transmissions of the exercises, sitting next to Lt. Gen. Herzi Halevi, the Israeli chief of staff.

Netanyahu’s new government is fragile, and his proposals to reduce the power of the Israeli judiciary have drawn fierce criticism, including massive street demonstrations in Tel Aviv and other cities. At such a delicate moment, the Biden administration probably wouldn’t want to do Netanyahu any favors. But this week’s exercise shows that U.S.-Israeli military cooperation is largely impervious to internal politics in either country.

According to the U.S. Central Command, which oversees American operations in the region, the exercise involved roughly 6,400 U.S. troops, 12 ships and more than 140 American aircraft. The Israelis contributed more than 1,500 troops, a Centcom statement said. Over four days, U.S. and Israeli forces dropped more than 180,000 pounds of live munitions.

In addition to the B-52 strategic bombers, the American arsenal on display this week included F-35 deep-penetration fighters, the USS George H.W. Bush aircraft carrier strike group, HIMARS rockets, armed Reaper drones and KC-46 tankers that could help Israeli or U.S. planes refuel on a mission over Iran.

Juniper Oak was a show of 21st-century combat power, involving “all aspects of warfighting — some of which are seen and some of which are not,” said Gen. Michael Erik Kurilla, the Centcom commander. Kurilla said in a statement on Thursday that the exercise had included simulated operations in space and cyberspace.

U.S. and Israeli military officials would not confirm officially that Juniper Oak was planned with Iran as a potential target. But that has been an open secret ever since the two countries began organizing the exercise in November.

The show of force comes as the Biden administration’s efforts to revive the 2015 Iran nuclear deal have stalled. The administration hasn’t formally withdrawn from its diplomatic efforts. But State Department spokesman Ned Price said this month that “a return to compliance with the [Iran nuclear deal] isn’t on the agenda … because the Iranians turned their back on it.”

Iran has pressed ahead with its nuclear enrichment program, ever since President Donald Trump withdrew from the deal in 2018, and now has breakout capability, according to Rafael Grossi, the head of the International Atomic Energy Agency. “They have amassed enough nuclear material for several nuclear weapons, not one, at this point,” Grossi said this week.

In the nuclear realm, deterrence is the essence of good strategy. And that’s the baseline for assessing this week’s rehearsal for a military attack on Iran. President Biden has said the United States will never allow Iran to acquire a nuclear weapon and that he would use force as a “last resort” to stop Tehran from going nuclear.

This week’s exercises makes that U.S. threat a little more credible — and, if the logic of deterrence holds, reduces the likelihood of an actual conflict. That’s the theory, at least. What Juniper Oak suggested was that a military action, if it ever came, would likely be massive.

Opinion by David IgnatiusDavid Ignatius writes a twice-a-week foreign affairs column for The Washington Post. His latest novel is “The Paladin.”