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Walking Dead Wiki
Walking Dead Wiki

Bombing of Atlanta.

Operation Cobalt also referred to as the "Sunset Protocol" by the US Marines, is the name given to the plan devised by the U.S. Military in order to contain the spread of the infection. Operation Cobalt also contained a contingency plan should the military lose control of the situation.

Initial Stage

The initial stage of Operation Cobalt was initiated three days after the initial outbreak began in the U.S.A., with the deployment of military units into major urban areas (such as Los Angeles, California or Atlanta, Georgia) after the outbreak overwhelmed local law enforcement. Once deployed, the units would set up easily defensible 'Safe Zones' in urban areas such as Safe Zone India in Los Angeles or around the CDC in Atlanta. Medical facilities and refugee centers, such as those in the Los Angeles Arena and Raynard Community College, would also be set up to secure those believed to be infected, provide screenings for the injured and sick, and to act as bases of operations.

Once these areas were set up, the safe zones would be used as a spring board to try to take back major metropolitan areas. The plan for the initial stage of Operation Cobalt can be described as follows:

  • Selected, easily defensible areas to be chosen for safe zones.
  • Medical facilities to be established for treating the ill and possibly infected.
  • Those brought to the medical facilities would be held in custody until either seen by a doctor or symptoms of the infection manifested.
  • Those who have either turned or showed signs of infection are to be humanely terminated, with their bodies being cremated.
  • National Guard/Army units to use safe zones to retake city.
  • The termination of infected outside the safe zones to commence. For unknown reasons, survivors remaining inside the city but outside of the safe zones would be terminated as well.
  • Be prepared to go to Contingency Plan.

Bombing of Los Angeles.

Contingency Plan

Operation Cobalt also contained a contingency plan should the initial stage fail. The contingency plan seems to be a late addition once those in charge realized that they were losing control. The contingency plan contained three key points;

  • Individuals in medical facilities to be humanely terminated.
  • Military units would withdraw during the night as not to panic the civilian population. They would withdraw to certain bases (Edwards Air Force Base being one).
  • Infected zones to be napalmed/bombed in order to terminate infected subjects and try to contain the further spread of the virus.

Cities Known to Have Been Bombed

The following cities are known to have been bombed:


The overall outcome of Operation Cobalt is unknown. By the time of its execution, most major population centers (at least, those west of the continental divide) had been overrun and military safe-zones were desperately low on supplies and morale. It is unknown if the bombing had any significant effect on the spread of the virus, as the pathogen had already infected the wider population, and many people had fled the cities in the initial panic. Nevertheless, the number of undead destroyed in the campaign is likely to be very high. The most marked outcome of Operation Cobalt (at least in the California area) seems to be ecological, however. According to a park ranger broadcasting from Shuteye Peak, the forests of Yosemite National Park and the Serra Nevada mountain range were on fire and likely to be gone in a week.

One significant outcome that occurred after the fall of California and other states west of the continental divide, is that National Guard units were now actively working alongside, if not subordinate to/entirely replaced by, the regular military. It can be assumed that this is why a helicopter from the 7th Cavalry is seen abandoned outside the hospital where Rick was recovering.

Another factor which remains unknown is what, if any changes, took place to Operation Cobalt after they abandoned Los Angeles. For example, in Lincoln, Nebraska, a commercial airline is seen crashed in the streets. It is unknown whether or not this plane came down due to any infected on board (as in the case of TruWest Airlines Flight 462) or whether or not it was shot down by the jets overhead. Also, in episode five of The Walking Dead: World Beyond, it is stated that the military destroyed all the bridges over the Mississippi River.

In the aftermath of Operation Cobalt, it is unknown to what extent the government or military remains active, but it can be assumed that due to the extremely high mortality and desertion rate, as well as the loss of infrastructure, there is little left in the way of a military command and control structure or government departments. It is possible however, that the remaining connected centralized forms of the United States government evacuated to higher altitudes such as in the mountains, to avoid the insurmountable waves of walkers. Subsequently to the initial outbreak a limited Mexican naval patrol was still operational in the waters around the USA-Mexico border a short time after Cobalt was enacted. Nevertheless, neither the U.S. Navy or Coast Guard had any part in this patrol - the Coast Guard broadcasting a statement that they could no longer provide aid via land, sea or air. Isolated groups of military personnel persisted years after the outbreak but had no connection to any command structure from the old world. By this time, it is certain that whatever remained of governmental or military hierarchy in the aftermath of Operation Cobalt has long since disintegrated.

Operation N.O.A.H.

According to conspiracy theorists broadcasting in the weeks following the collapse, the U.S. government was responsible for the outbreak, which was an attempt at population control that went wrong. It is suggested that they had a plan should the contingency of Operation Cobalt fail. The plan was entitled Operation N.O.A.H. and it matches the real life continuity of government plan. Little is known about Operation N.O.A.H. other than it authorized the evacuation of government figures to locations unknown.


  • The name of the operation was first heard over a military radio by Daniel Salazar when he was torturing Andrew Adams in the basement of Susan Tran's empty home.
  • Cobalt is also the name of the episode in which the name of the operation was heard.
  • Operation Cobalt was also in use when the military was dealing with the outbreak in Atlanta, as Shane, Lori, Carl, Carol, Sophia and Ed were making their way to a purported safe zone in Atlanta, before witnessing it being bombed by the military.
  • It is unknown whether or not members of the Federal Government were involved in the decision making process of Operation Cobalt, but it is likely, taking the Geneva Convention into consideration.
  • Cobalt was the original place holder name for Fear The Walking Dead.
  • It is unknown at what point the changeover from National Guard units to regular military units happened or whether or not this was part of Operation Cobalt. Whether the National Guard was federalized or the regular army was mobilized to operated on U.S. soil via a vote of congress in unknown.
  • At some point following the bombings, the Army and National Guard engaged in a war between one another.
  • There is some confusion as to the status of San Diego. While George Geary names San Diego as one of the cities bombed, Brandon Luke and his friends maintained that San Diego had not been bombed.
    • Although given the fact that Brandon's group was in Baja California during the initial outbreak it's possible that they don't know the full extent of the apocalypse and its aftermath in the US.