Trump had not bothered to read the letter and missed the jab until he saw media coverage pointing it out. Realizing that he had been dissed, Trump abruptly announced that he would install Patrick Shanahan, the deputy defense secretary, as acting secretary as of January 1 rather than wait until the February 28 departure date Mattis had set, effectively pushing him out the door two months early. Only Trump would fire someone who had already quit.
