Normally I wouldn’t comment on the odd fact that it took the Pentagon three and a half days to inform anyone at the White House — including National Security Adviser Jake Sullivan — that Defense Secretary Lloyd J. Austin III had been hospitalized following complications from an elective procedure.

Austin was admitted to the intensive care unit at Walter Reed National Military Medical Center in Bethesda, Maryland, last Monday. But senior defense officials say they didn’t know about it until Thursday. The Pentagon then informed the White House.

I’ve been thinking a lot recently about the chain of command in military decision making, including over the wars in Gaza and Ukraine. As defense secretary, Austin is second only to Biden in that chain.

There’s supposed to be a system for knowing where the secretary of defense is at all times.

When I was secretary of labor (hardly as important an office as defense secretary) my staff reported daily to the White House on my schedule and whereabouts. It would have been impossible if not unthinkable for me to be hospitalized for three days without the White House knowing.

Besides, I had to be on call because I was number 11 in the order of presidential succession if the president became incapacitated, died, or was removed from office. The secretary of defense is number 6. I didn’t expect to be thrust into the job, but even the remote possibility meant I had to be reachable.

But let’s give Austin the benefit of the doubt. He’s known as a private person, disinclined to impose his personal issues on anyone else. I wish him a speedy recovery.

In any event, the Pentagon seems to have functioned fine without knowing where he was.

All this has got me thinking about Trump’s preparations for assuming power if he’s reelected president. (Some of these preparations can be found in a chilling document called Project 25.)

These include the threat of using federal troops against those who might protest his policies and practices.

Earlier this year, Trump said at a rally in Iowa that he’d unilaterally send the military into Democratic-run cities. “You look at any Democrat-run state, and it’s just not the same — it doesn’t work,” he said, referring to cities like New York, Chicago, Los Angeles, and San Francisco as crime dens. “We cannot let it happen any longer. And one of the other things I’ll do — because you’re supposed to not be involved in that, you just have to be asked by the governor or the mayor to come in — the next time, I’m not waiting.”

If you think Congress or the federal courts would stop him, think again. As head of the executive branch of government, Trump could theoretically ignore whatever the other two branches told him to do or not to do, because a president is the only one with power to “execute” the laws.

And the core of that power is a president’s command over the military.

I don’t want to alarm you, but if Trump is reelected, everything could come down to whom Trump appoints as his secretary of defense, and the top generals whom that secretary appoints. (The secretary of Homeland Security could also play a key role.)

Might doesn’t make right, of course — which is exactly why it’s important to be aware of Trump’s potential for using the military to get his way.

Throughout history, the only real check on dictators has been the military. Dictators rely on their militaries. Militaries enable dictatorships. Militaries are behind most coups d’etat.

As Abraham Lincoln wrote to Major General Joseph Hooker, “I have heard … of your recently saying that both the Army and the Government needed a Dictator. Of course it was not for this, but in spite of it, that I have given you the command.”

Viewed this way, perhaps we should be grateful that we live in a society where a secretary of defense can go missing for three and a half days and no one notices.

— Robert B. Reich is a columnist with Tribune Content Agency.