Transcript: Robert O'Brien on "Face the Nation," Sept. 24, 2023

The following is a transcript of an interview with former national security adviser Robert O'Brien that aired Sunday, Sept. 24, 2023, on "Face the Nation."

MARGARET BRENNAN: We turn now to Robert O'Brien. He served as national security adviser under former President Trump and he joins us this morning from Park City, Utah. Ambassador, it's good to have you here with us.