evidence: Early in the military career of recently retired Marine Gen. David Berger, he and his wife, Donna, whom he had met when they were in sixth grade, made a promise to each other. [...] Berger’s last assignment before pinning on a fourth star as commandant in 2019 was as the commanding general of Marine Corps Combat Development Command, which develops and implements the very concepts at the center of Force Design. [...] Berger’s departure marked the first time the Marine Corps has been left without a Senate-confirmed leader in more than a century. Smith, as the second-in-command, assumed the role of acting commandant upon Berger’s retirement at Marine Barracks Washington.