Former Vice President Dick Cheney and his daughter Liz Cheney were pretty clear about one thing on Monday: Sen. Rand Paul (R-KY) is “out to lunch” on foreign policy.

At an event hosted by Politico on Monday featuring the former vice president, Liz Cheney, and the former vice president’s wife, the elder Cheney and his daughter both expressed skepticism about Sen. Rand Paul (R-KY) on foreign policy.

“Obviously, Senator Paul leaves something to be desired when it comes to national security policy,” Liz Cheney said. Cheney added that she has some “big concerns about the way Senator Paul seems to think we can be safe” through an isolationist approach.

Later on during the event the former vice president was asked if he thought Paul would be dangerous as president of the United States.

“I said I didn’t want get into endorsing or criticizing anyone. I did express the view that I think isolationism is crazy,” the former vice president said. “Anybody who went through 9/11 who thinks we can retreat behind our oceans and will be safe and secure is — I’m sorry but they’re out to lunch.”

Their comments come as Paul and Texas Gov. Rick Perry (R) are engaged in a public feud over foreign policy. The latest shot by Paul came in a piece in Politico Magazine on Monday where the senator was responding to an op-ed by Perry in The Washington Post.

“Perry says there are no good options. I’ve said the same thing,” Paul wrote. “President Obama has said the same thing. So what are Perry’s solutions and why does he think they are so bold and different than anyone else’s?”

Both Perry and Paul have hinted that they are considering running for president in 2016.