“Jackie”

He goes by his call sign, and holds, in his words, the illustrious rank of sergeant — the same one he had in the U.S. Army, where he was a cavalry soldier and a Bradley Master Gunner. He crossed into Ukraine in March 2022, was wounded almost immediately, and spent his first weeks in a Ukrainian hospital working out who he was fighting for. He joined the 3rd Assault Brigade in 2023 during its post-Bakhmut workup and is now the senior American military advisor to the Third Army Corps and its staff, where he stood up the corps’ sergeant’s course with his commander and teaches Western mission command — trust, honesty, initiative — to the units spreading Third Corps’ culture across the Ukrainian armed forces. He appears by call sign only, for the same operational-security reasons he gives on tape.

Photo: still from Episode 22, filmed in Kyiv.