- "Step One: Kill the Infected. Step Two: Containment. If containment fails... Step Three: Extermination."
- ―Scarlet explains the stages of Code Red.
Code Red was a military protocol for the US Army to use against the Infected, should a Second Outbreak of the Rage Virus occur in London. It was to be primarily carried out by the U.S. Army, but also called for close air support from the U.S. Air Force.
The first step of Code Red is to lock down the affected area, closing off all routes of escape. Next, the military lock all of the uninfected populace in safe rooms to protect them against the threat of the roaming Infected.
If the first step fails, the Army proceed to kill the Infected and save those who escape infection, with the overall goal being to contain the spread of the infection. If that should fail, then the next step is "Extermination"- killing everyone the military can find who is not one of them, infected or not.
To back up the Extermination phase of the plan, the U.S. Air Force will firebomb the whole of District One, looking to kill everyone on the streets and low levels of buildings quicker than soldiers with small arms could do. Another step in the Extermination phase is the use of lethal poison gas to wipe out the remaining Infected in London who may have escaped or survived in the lockdown area. (28 Weeks Later, 28 Days Later (comic series)) Soldiers wearing MOPP Level 4 suits and armed with flamethrowers would advance into the gassed city streets to burn anyone who managed to survive, while Apache attack helicopters patrolled above.
28 Weeks Later
Code Red was executed in full upon the commencement of the Second Outbreak of the Rage virus. Infected managed to survive the firebombing, were missed by the poison gas and flamethrowers, and otherwise remained at large after all steps of the plan had been carried out.
Due to unknown means, the Rage virus got across the English Channel and swiftly began to overrun Paris. It is unknown if the U.S. Army and the French Army, both of whom are NATO members, shared battle plans or if NATO, the French military, or U.S. Armed Forces Europe were ready to or improvised some form of the Code Red plan to respond to the outbreak in Paris.
- F-15E Strike Eagles are seen dropping napalm bombs, to wipe out the Infected in London. However, in real life, the Air Cavalry, who were mentioned by Flynn as the ones responsible for the firebombing, use helicopters.
- F-15 fighters operated by the United States are flown by the U.S. Air Force, versus the Air Cavalry, which is part of the U.S. Army, so both were part of the NATO force sent to London and both had their respective roles in the Code Red plan.
- MOPP is Mission Oriented Protective Posture, the U.S. Army's name for its chemical weapons protection gear. MOPP Level 4 means wearing everything- suit, boots, mask, and gloves. That would be standard for soldiers operating in an environment where poison gas has been deployed.
- Of all aspects of the American military's Code Red plan, the safe rooms were the most woefully inadequate. Securing standard, unmodified, pre-infection doors with chains and a padlock were shown in 28 Weeks Later as insufficient to keep a crowd of panicked civilians in, or just one infected (Don Harris) out. Survivors of the first outbreak, especially British intelligence, military, or first responders, could easily have testified that those means were not good enough. Doors strong enough to withstand any abuse from human hands and feet could have successfully protected the civilians and given the military sufficient time to hunt down and kill the infected Don Harris.