The D Brief: Trump militarizes border, testing courts; Adm. Caudle for CNO?; Tariff war could cost DOD critical minerals; And a bit more.

The Trump administration wants to turn a long stretch of the U.S.-Mexico border into an Army base in an extraordinary move that’s likely to be challenged in court, U.S. officials told the Associated Press on Monday, three days after the White House released a memo entitled, “Military Mission for Sealing the Southern Border of the United States and Repelling Invasions.” In that memo, President Trump said he wanted this border-militarization plan to be implemented within 45 days.