“You don’t know that I’m going to even do it. I may do it. I may not do it. I mean, nobody knows what I’m going to do.”

So said the president on Wednesday in one of those streams of semiconsciousness with which he informs us of his fluid intentions. He was musing about intervening in Israel’s war against Iran. As usual, the reiterated first-person-singular pronoun was his message. When he knows what he wants to do, everyone, including Congress, for which governance has become a spectator sport, will know because he will already have done it.

As this is written Thursday afternoon, one question is whether he will order bombers to deliver, as only they can, the only conventional (i.e., nonnuclear) munition that can destroy the most hardened target in Iran’s nuclear weapons program. There is a strong argument for doing this. It would, however, be not only polite but prudent for the president to make the case to the public. And although at this stage in our institutional decay it seems quaint to say so, it would be constitutionally proper for Congress to be somehow involved.

Last weekend, many Americans — mostly progressives, surely — staged “No Kings” protests against what progressivism has done much to produce: today’s rampant presidency. Their chief concerns were domestic — unilateral spending cuts, deportations, etc. A week is, however, forever in today’s politics. Today, progressives, those occasional constitutionalists, are fretting about uninhibited presidential warmaking.

On Tuesday, Barack Obama descended from Olympus in his usual lecture mode, solemnly sharing his worries about Washington tendencies “consistent with autocracies.” Obama is and was a situational Madisonian. He rewrote immigration law after repeatedly and correctly insisting he had no legitimate power to do so. And he intervened in Libya’s civil war by waging war there for almost eight months without seeking congressional authorization or complying with the law (the War Powers Resolution). Obama argued, through his lawyers, that the thousands of airstrikes that killed thousands did not constitute “hostilities.” Harvard law professor Jack Goldsmith termed Obama “a matchless war-powers unilateralist.”

Presidents, who, unlike Congress, are always on duty and can respond to crises with dispatch, are preeminent in foreign affairs. But not autonomous: Pertinent powers are shared with Congress. It is vested with the power (which it has largely sloughed off) to “regulate commerce with foreign nations.” The president is commander in chief of the armed forces, but Congress raises them. Presidents wage wars; Congress declares them. The Senate must consent to treaties the president negotiates. In his 2015 book on the framers’ creation of the presidency (“Imperial From the Beginning”), University of Virginia law professor Saikrishna Prakash notes that, in the Embargo Authorization Act of 1794, Congress authorized the president to impose an embargo — but only for 15 days and only when Congress was not in session.

The Justice Department’s executive-friendly Office of Legal Counsel has repeatedly said that the constitutional propriety of president-initiated military actions must be judged by their “nature, scope, and duration.” In “The President Who Would Not Be King: Executive Power Under the Constitution” (2020), Stanford law professor Michael W. McConnell says the OLC’s criteria have legitimated unilateral presidential uses of force involving many billions of dollars and thousands of deaths in Libya, Bosnia and Somalia:

“Even if the constitutional text does leave some room for the President to initiate hostilities short of full-bore war on his own authority, it is hard to believe that executive power can properly be stretched as far as it has in recent times. The military engagement in Libya … was in no sense defensive, nor was there anything sudden about it. The president consulted for months with the United Nations and European allies, but did not go to the United States Congress.”

Prakash notes that “‘monarch’ comes from ‘mono,” meaning ‘one’ or ‘single,’ and ‘arch,’ derived from ‘archon,’ meaning ruler.” Today’s first-person-singular-pronoun president said Wednesday, “I have ideas as to what to do” and “I can go from one extreme to the other” and “I like to make a final decision one second before it’s due.”

Congress last declared war many wars ago, on June 5, 1942, when, to clarify legal ambiguities during a world conflagration, it declared war on Hungary, Romania and Bulgaria. Today’s issue is not whether war on Iran should be formally declared but whether constitutional good manners, prudent sharing of responsibility, and a decent respect for the public and its elected representatives require acting other than monarchically.

George Will is a Washington Post columnist.