Retired Marine General Jim Mattis is the last man standing from President Donald Trump’s original national security team.  But how long can the Defense Secretary last?  Mark Perry, the author of the new book, THE PENTAGON’S WARS joins us to talk about what happens when there’s friction between the leaders at White House and the Pentagon.  Gen. Mattis tends to take a less ideological approach than his new partners, Secy of State Mike Pompeo and Natl Security Advisor John Bolton, not to mention the President who hired them.