evidence: President Donald Trump tweeted Wednesday the only thing he and former President Barack Obama have in common is "that we both had the honor of firing Jim Mattis." The tweet came after Mattis, a retired Marine Corps general, criticized Trump's response to the protests being carried out across the nation since the police killing of George Floyd, an African-American man in Minneapolis, Minn. Trump didn't fire the general. Mattis served as his secretary of Defense from 2017, when he was confirmed by the Senate, until he tendered his resignation in December 2018 as he disagreed with Trump's decision to pull U.S. troops from Syria, according to U.S. officials. In the letter, he said his views and beliefs in foreign policy and strategy didn't align with those of the president.