Overnight Defense: State Dept. watchdog was investigating emergency Saudi arms sales before ouster | Pompeo says he requested watchdog be fired for ‘undermining’ department | Pensacola naval base shooter had ‘significant ties’ to al Qaeda, Barr says

Happy Monday and welcome to Overnight Defense. I’m Rebecca Kheel, and here’s your nightly guide to the latest developments at the Pentagon, on Capitol Hill and beyond. CLICK HERE to subscribe to the newsletter.THE TOPLINE: The State Department inspector general who was fired Friday night was investigating the Trump administration’s controversial use of emergency powers to push through arms sales to Saudi Arabia.House Foreign Affairs Committee…