Questions About Assassinations Test the Limits of Trump’s Immunity Claim

“It is clear that as president, I will be bound by laws just like all Americans,” Donald J. Trump said in 2016, during his first campaign.

Times have changed, and he now says the opposite. Next week, the Supreme Court will consider his claim that he is immune from prosecution on charges that he plotted to subvert the 2020 election.

His 2016 statement, now largely forgotten, was not an off-the-cuff remark. It was, rather, a considered effort to put to rest a controversy over a question that has recently also figured in the case before the Supreme Court: May the president order the military to conduct unlawful killings?

In January, at an appeals court argument, Judge Florence Y. Pan asked Mr. Trump’s lawyer a question meant to test the limits of his argument that presidents are immune from prosecution for their official acts.

“Could a president who ordered SEAL Team 6 to assassinate a political rival, who was not impeached, would he be subject to criminal prosecution?” she asked.

The lawyer, D. John Sauer, said no.

Mr. Sauer does not seem eager to revisit the question in the Supreme Court. Indeed, in asking the court to hear Mr. Trump’s appeal, Mr. Sauer urged the justices not to be distracted by “lurid hypotheticals” that “almost certainly never will occur.”

The prospect of ordering the military to conduct unlawful killings is certainly lurid. But it has crossed Mr. Trump’s mind.

Indeed, early in his first campaign, Mr. Trump vowed to order the military to kill the relatives of terrorists.

“We’re fighting a very politically correct war,” Mr. Trump said in 2015, referring to efforts to defeat the Islamic State. He added: “The other thing with the terrorists, you have to take out their families.”

In an interview at the time, Michael Hayden, the retired Air Force general who has directed both the National Security Agency and the C.I.A., said such an order would be unlawful and that military personnel would be required to refuse to follow it.

Asked about Mr. Hayden’s statement at a Republican primary debate in March 2016, Mr. Trump said the military would follow his instructions.

“They won’t refuse,” he said. “They’re not going to refuse me. Believe me.”

The next day, though, in a rare move, Mr. Trump walked back his remarks in a statement that seemed prepared by his advisers.

“I will use every legal power that I have to stop these terrorist enemies,” he said. “I do, however, understand that the United States is bound by laws and treaties and I will not order our military or other officials to violate those laws and will seek their advice on such matters.”

He added: “I will not order a military officer to disobey the law. It is clear that as president I will be bound by laws just like all Americans and I will meet those responsibilities.”

Mr. Trump and his lawyers have stopped walking things back, and these days they embrace a maximalist position. At the same time, they do not seem inclined to talk about whether presidents can be held to account for abusing their powers as commander in chief.

But the justices may find the topic hard to avoid, if only because three groups of former military and national security officials have filed friend-of-the-court briefs exploring the matter.

In one, filed in support of Mr. Trump, three former military leaders wrote that there was nothing to fear because military personnel would not carry out unlawful orders.

“Any presidential order to the military to use lethal force without legal justification would be an order calling for the commission of a grave felony crime,” the brief said. “And any military officers who knowingly issued or carried out such an unlawful order would themselves be criminally liable.”

Two other briefs, filed in support of Jack Smith, the special counsel in the case, were not so sanguine. They agreed that members of the military must refuse to obey unlawful orders. But they said presidents emboldened by the knowledge that they are immune from prosecution would put grave and dangerous pressure on those they command.

A brief from retired admirals and generals, along with former secretaries of the Army, Navy and Air Force, said that “the duty to disobey would be an unacceptably thin fail-safe against a president who was intent on flouting and who was permitted to flout the law without the possibility of criminal prosecution.”

A third brief, from national security and military experts, said that presidential immunity coupled with the power to pardon crimes would be a recipe for wholesale lawlessness.

“For example, in the SEAL Team 6 assassination scenario, the team members would not need to fear the consequences of committing murder,” the brief said, “if the order to commit the murder were coupled with the promise of a pardon.”