Trump Fires Defense Secretary Esper Via TwitterU.S. President Donald Trump has fired Defense Secretary Mark Esper via Twitter. “Mark Esper has been terminated. I would like to thank him for his service,” Trump wrote Monday. ...Chris will do a GREAT job! Mark Esper has been terminated. I would like to thank him for his service. Esper had been expected to serve through the transition period between now and President-elect Joe Biden’s inauguration in late January 2021. Christopher Miller, the Director of the National Counterterrorism Center, will serve as acting secretary of defense, “effective immediately,” according to Trump’s tweets. In recent days, some media outlets reported Esper had written his resignation letter, while others quoted officials saying the defense secretary had no plans to resign. Trump and Esper’s relationship reportedly has been tense since a rift in June. Days after the president threatened to deploy active-duty forces to quell protests against police violence and racial injustice, Esper publicly declared his opposition to any such move. Esper served as defense secretary since July 2019. Before his appointment by President Trump, Esper, an Army veteran, served as secretary of the Army from 2017 to 2019.