President Trump’s national security staff has endured unusually high turnover—which makes Gen. Joseph Dunford’s continuity at the Joint Chiefs of Staff all the more important. The career Marine previously served as commander of U.S. forces in Afghanistan; that experience makes him a valuable resource for a President eager to project strength without entangling U.S. forces too deeply in commitments abroad.

Dunford has also helped shape sharp-turn directives from the White House into pragmatic policy—including, earlier this month, converting a mandate to get the military more involved in providing security on the Mexican border into a strategic deployment of National Guard troops that earned widespread support.

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