Former CIA Director Michael Hayden says if a president Donald Trump follows through with some of the things he's said on the campaign trail, the military would refuse to act.

In an appearance this week on HBO's "Real Time with Bill Maher," Hayden said he would be "incredibly concerned if a president Trump governed in a way that was consistent with the language that candidate Trump expressed during the campaign."

When asked for specifics, Hayden, also a former director of the National Security Agency, mimicked Trump.

"'Well, we're going to do waterboarding and a whole lot more because they deserve it. We did tough stuff,'" Hayden said.

"What about killing the terrorist's family?" Maher asked, referring to Trump's suggestion that intentionally taking out their families would defeat the Islamic State. "I mean, that never occurred to you, right?"

"God no," Hayden replied.

"Let me give you a punchline. If he were to order that once in government, the American armed forces would refuse to act."

Maher seemed surprised by the statement.

"What? That's quite a statement sir," Maher posited. "I thought the whole thing was you have to follow orders."

"You cannot — you are not committed, you are not required," Hayden said. "In fact you are required not to follow an unlawful order that would be in violation of all the international laws of armed conflict."

Maher said Hayden had provided a "great reason" not to support Trump.

"There would be a coup in the country," Maher added.

"I'm serious," Hayden said.

"I think it's a coup that you said it," Maher said.