The Pentagon’s belated disclosure that Defense Secretary Lloyd J. Austin III was hospitalized twice without informing President Biden touched off a controversy that isn’t likely to end quickly.

Austin’s defenders argue that his absence had no real-world consequences. The Pentagon says his deputy, Kathleen Hicks, was in charge while he was out of commission. And they point out that Austin has taken responsibility for the lapse.

But those excuses ignore an important element in this baffling episode. Austin committed a serious political blunder: He made it look as if Biden isn’t exercising clear command over his Cabinet.

The Defense secretary blindsided his boss, an error that’s serious in almost any organization, civilian or military.

Worse, especially in an election year, he played right into a favorite anti-Biden narrative of Republicans: their charge that the president is weak and ineffective.

Voters often say that when they consider candidates for president, they want a strong leader. Polls have found that former President Trump, the likely Republican nominee, outscores Biden on that measure in most Americans’ eyes, fairly or not.

Austin inadvertently strengthened the GOP’s argument. Biden’s critics wasted no time using the club he handed them.

“It raises questions about Joe Biden’s competence, or that he’s really in charge at the White House,” said Sen. Tom Cotton of Arkansas, referring to Austin’s AWOL episode. “If this administration would conceal a mere elective minor surgery for a Cabinet secretary, what might they be concealing about Joe Biden’s health?”

That attack was off-target; there’s no evidence that anyone other than Austin concealed his surgery. But the fact that Austin concealed his hospitalizations from the White House was bad enough.

“This wasn’t a crime; it was a blunder,” said Peter Feaver, an expert on civil-military relations at Duke University who served on the National Security Council staff in both Democratic and Republican administrations. “It interfered with the contrast the president is trying to draw between chaos and adult leadership” — Biden’s claim that he restored competence and calm to the federal government, in contrast with the chaos of the Trump years.

As of Sunday, Austin was still at the Walter Reed National Military Medical Center, nearly two weeks after he checked in a second time. A Pentagon spokesman said he didn’t know why the secretary’s hospital stay had been extended.

“I take full responsibility for my decisions about disclosure,” Austin said in a written statement from the hospital. “I recognize I could have done a better job.”

Austin has been famously protective of his privacy. He keeps his public appearances to a minimum. He spends relatively little time with members of Congress. He steers clear of the Pentagon press corps.

But those choices have come at a price. The Defense secretary, a retired Army general, has shown himself to be politically tone-deaf.

That weakness isn’t unknown among military officers. Political savvy isn’t a required core competency in the infantry.

“Most generals — even smart, successful four stars — have little experience navigating a strategic environment in which everything is political,” said Rosa Brooks, a Georgetown professor who worked in the Pentagon during the Obama administration.

That’s one reason six of the last 12 Defense secretaries have been politicians. Only two have been career military officers — Austin and retired Marine Gen. James N. Mattis, who served under Trump.

The White House made it clear that in its official view, Austin’s failure to communicate was a serious error.

“It is not optimal … for a situation like this to go as long as it did,” National Security Council spokesman John F. Kirby said in a painfully understated rebuke.

But Kirby added that Biden has “full confidence” in Austin and does not plan to fire him.

Biden doesn’t fire subordinates often. Aides say he likes and admires Austin. And he doesn’t need a distracting confirmation process for a new secretary during an election year.

But Austin has made him look like a weak, indulgent manager at a time when Biden is trying to cast himself as a strong, decisive leader.

There’s a partial remedy for this problem.

Austin should submit his resignation to Biden — publicly, to make it clear that he recognizes his error and didn’t intend to disrespect the president.

Biden can accept the resignation or refuse it. It would give him an opportunity to show who’s in charge.

Either way, the controversy isn’t going to disappear overnight. The Pentagon has launched a 30-day review of what went wrong. Its inspector general has begun a separate inquiry, which will take longer.

And members of Congress say they intend to hold hearings, which will focus mostly on whether the Pentagon’s claim that there was never a hiccup in the chain of command holds up.

Austin may have to talk about his medical history more than he ever wanted.

He deserves sympathy, of course, as a 70-year-old man facing a cancer diagnosis. But Biden deserves sympathy too. A president shouldn’t have to suffer needless political damage thanks to one of his own appointees.