Schrader

 was Colonel Heinrich Konrad's second in command. He didn't like the fact that Brigadier Lethbridge-Stewart was called to help at Kriegeskind. He ordered a lockdown of the base, but that didn't stop the Third Doctor from entering it. He launched the Arclight protocols, which would destroy a base to stop it falling into alien hands. He mistrusted the Doctor, and didn't want to stop his attack because of the Doctor's discoveries. (AUDIO: Old Soldiers)