President Trump didn't tell mattis himself, instead, according to defense and administration officials, Secretary of State Mike Pompeo had to make the call this morning. Afterward the president made the firing public, tweeting Deputy Secretary of Defense Patrick Shanahan will assume the title of Acting Secretary of Defense starting January 1st 2019. Mr. Trump is frustrated, according to several administration sources, specifically at reports which said mattis was quote "the last adult in the room".
The two were increasingly at odds, but the president's decision to withdraw troops from Syria was the breaking point for the defense secretary. Mattis's resignation letter offered a clear rebuke of the president's worldview, particularly the treatment of NATO allies. Mattis wrote the president deserved a Secretary of Defense whose views were better aligned with his. The president took a swipe at Madison Saturday on Twitter, mentioning his previous firing in the Obama administration. Given mattis's popularity at the Pentagon, other departures may follow. Shanahan who takes over as Acting Secretary on New Year's Day spent three decades as an executive at Boeing and the last 17 months of the Pentagon focused on cutting wasteful spending.
Since then scholars have been at odds on how to interpret it.
When a failure happens on one server, then this standby adapter takes over all connections from the other server.