WASHINGTON (AP) – President Donald Trump says he has fired Defense Secretary Mark Esper. This is an unprecedented move at a time of national uncertainty about the outcome of Trump’s bid for a second term. It is the first time in the post-World War II era that a president seeking reelection has removed his secretary of defense after Election Day. The conventional wisdom is that stability atop the Pentagon and the military be maintained during a possible transition to a new administration. Esper was Trump’s second defense secretary, succeeding Jim Mattis, who resigned in 2018.