Marine Gen. James Mattis, who leads U.S. Central Command, is being replaced by the Obama administration despite an admirable performance record, Mackubin Thomas Owens writes. The decision, which may be due to Mattis' disagreements with the White House over Iran and the Middle East, reflects Obama's recent preference for military leaders who won't object to military spending cuts. "By pushing Gen. Mattis overboard, the administration sent a message that it doesn't want smart, independent-minded generals who speak candidly to their civilian leaders," Owens writes.