Retired Navy Admiral Steve Abbott appeared on Morning Joe today to emphasize that Kamala Harris is prepared to lead -- but Donald Trump isn't. Abbott is part of the National Security Leaders for America, with more than 700 former and retired senior military leaders and public servants who have denounced Trump and back Kamala Harris.

"She's been on the Senate Intelligence committee. She's traveled extensively, interacted with leaders around the world in many, many countries, and she has been with President Biden for 3 1/2 years in the Oval Office and in the Situation Room dealing with national security issues," he said.

"So she has the experience that she needs. She's been a strong proponent of our position with respect to Ukraine, the support of Ukraine against the Russian invasion. Strengthen NATO, make it larger and more effective than it's ever been. And she understands our strategic concerns in the Indo-Pacific, in South America, in Africa, in all of the regions of the world. She's well-positioned to take on the responsibilities as president and commander in chief."

"As it pertains to Ukraine and NATO and Russia and the Indo-Pacific, does Donald Trump understand your concerns?" Mika Brzezinski.

"Well, Donald Trump, frankly, is unfit to be the president of the United States. I know at the top of your show, you mention Vice President Cheney, who asked me to come to the White House to work on a study for him in the summer of 2001. He said the same thing. Donald Trump is, indeed, not fit to be the president of the United States. I believe he's not a disaster waiting to happen. He's a disaster which has already happened," he said.