Scoop: Key W.H. national security aide Andy Baker is departing

White House deputy national security adviser Andy Baker is leaving the administration in the coming weeks. Why it matters: Baker, who also served as national security advisor to Vice President Vance, was among the staffers most central to the administration's foreign policy and national security decision-making over the last 18 months. Baker was also personally involved in negotiations with Iran this year. Cliff Sims, who succeeded Baker as Vance's national security adviser earlier this…