Julius Robert Oppenheimer (born April 22nd, 1904) was a nuclear physicist working under the command of SRPA and was one of the scientists responsible for creating the United States' first fission bomb.
In the comics, Dr. Oppenheimer was present at Fort Anchorage, Alaska on January 1951 when the Chimera invaded and overran Anchorage. The attack left Oppenheimer as the only sole survivor of the base after staying hidden inside the base's bunker where his colleagues had developed the "atomics". After four days of hiding, Oppenheimer learned of the base's situation and hadn't mustered the courage of leaving the building. During those days, Oppenheimer learned of the Chimera's sudden presence in Alaska was due to the recreated Bering-bridge caused by the invaders' weather-changing technology and allowing them to easily march from Russia into North America by land.
While synthesizing an aerosol into acid that would eradicate the cocoons harboring the Grims inside the base's hangar, he was inadvertently discovered by Sentinel Team Alpha. While explaining the situation and his information of the Bering-bridge to Alpha Team, he was suddenly attacked by a hatched Grim before being saved by one of the Sentinels SPC. Waldron. Realizing that the Grim nest had hatched, Oppenheimer and Alpha attempted to escape the building to the mess hall; however, Oppenheimer was wounded by one of the Grims during the escape. He was made, however, comfortable by the Sentinels to recover from his wounds. He and Alpha made an attempt to escape Anchorage along with an active hydrogen bomb by tank, but only to be unexpectedly abducted by a Chimeran airship. Oppenheimer was revived via blood transfusion by Alpha's Lt. Murphy and was told by him that he (Murphy) intended on saving his men by having Oppenheimer bailing themselves out of the ship on the tank while Murphy stayed behind and sacrificed himself in activating the bomb. Oppenheimer did what he was told and ultimately died from the impact.
Consequently, Oppenheimer's death greatly hindered the American effort in recreating the bomb in which SRPA placed the blame on Alpha. Although, Oppenheimer's forewarning on the Bering-bridge was heeded by Alpha in which Joseph Capelli defended Lt. Murphy's action as the bomb's detonation had also destroyed the ice-bridge and irradiating the entire area, making it impossible for the Chimera to cross over America.