Trying to incite a military coup is sedition.

 Ms. Pelosi also said she had spoken with Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff, about “preventing an unstable president from initiating military hostilities or accessing the launch codes.”

A spokesman for General Milley, Col. Dave Butler, confirmed that the two had spoken and said the general had “answered her questions regarding the process of nuclear command authority.”

But some Defense Department officials have privately expressed anger that political leaders seemed to be trying to get the Pentagon to do the work of Congress and Cabinet secretaries, who have legal options to remove a president.

Mr. Trump, they noted, is still the commander in chief, and unless he is removed, the military is bound to follow his lawful orders. While military officials can refuse to carry out orders they view as illegal, they cannot proactively remove the president from the chain of command. That would be a military coup, these officials said.