As former leaders in the Defense Department — civilian and military, Republican, Democrat and independent — we all took an oath upon assuming office “to support and defend the Constitution of the United States,” as did the president and all members of the military, a fact that Gen. Milley pointed out in a recent memorandum to members of the armed forces. We are alarmed at how the president is betraying this oath by threatening to order members of the US military to violate the rights of their fellow Americans.