Fears That Trump Might Launch a Strike Prompted General to Reassure China, Book Says

“I continually reminded him,” General Milley is quoted as saying, “depending on where and what you strike, you could find yourself at war.”

Later that day, General Milley spoke to Speaker Nancy Pelosi, who was growing increasingly concerned Mr. Trump would lash out and use military force.

“This is bad, but who knows what he might do?” Ms. Pelosi said. “He’s crazy. You know he’s crazy. He’s been crazy for a long time. So don’t say you don’t know what his state of mind is.”

“Madam Speaker,” General Milley said, “I agree with you on everything.”

General Milley, who as the president’s top military adviser is not in the chain of command, tried to reassure Ms. Pelosi that he could stop Mr. Trump.

“The one thing I can guarantee is that as the chairman of the Joint Chiefs of Staff, I want you to know that — I want you to know this in your heart of hearts, I can guarantee you 110 percent that the military, use of military power, whether it’s nuclear or a strike in a foreign country of any kind, we’re not going to do anything illegal or crazy,” he said.

“Well,” Ms. Pelosi said, “what do you mean, illegal or crazy?”

“I can give you my word,” General Milley said. “The best I can do is give you my word and I’m going to prevent anything like that in the United States military.”

After speaking to Ms. Pelosi, General Milley convened a meeting in a war room at the Pentagon with the military’s top commanders, telling them that he wanted to go over the longstanding procedures for launching a nuclear weapon. The general reminded the commanders that only the president could order such a strike and that General Milley needed to be directly involved.