Donald Trump has named the acting heads of national-security agencies—all career federal executives—to serve until Senate-confirmed nominees are in place, according to a White House press release issued soon after the inauguration on Monday. Some of the officials will serve in the roles for just a few days, though others could stay on for longer as bruising confirmation battles play out. One has already been supplanted, by Secretary of State Marco Rubio, approved unanimously by the Senate on Monday afternoon. Trump has yet to name a nominee for the U.S. Agency for International Development. He is not expected to retain...