Trump pushes Mattis out two months early after resignation letter's coverage

Defense Secretary Jim Mattis announced his resignation on December 20, 2018, in a letter telling Trump he deserved a defense secretary "whose views are better aligned" with his own, widely covered as an implicit rebuke of Trump's Syria withdrawal decision and broader approach to alliances. On December 23, Trump tweeted that Deputy Secretary Patrick Shanahan would become acting defense secretary starting January 1, 2019, moving Mattis's departure up roughly two months from the late-February date specified in Mattis's own letter. The New York Times reported that Trump's public tone toward Mattis cooled and his irritation grew as coverage characterizing the letter as a rebuke spread, and that this contributed to the decision to accelerate the exit. The same day, Trump tweeted that he had given Mattis "a second chance" after President Obama "ingloriously fired" him, a characterization of Mattis's earlier departure from military command that recast the circumstances surrounding his own defense secretary's exit.