Earth Defense Force
The Earth Defense Force (EDF) is one of the few elements from the first Red Faction that has remained with the series into Red Faction: Guerrilla.
Red Faction
In Red Faction, Parker calls in the EDF to take control of Mars away from Masako's mercenaries and Ultor's guards. The game ends with the EDF broadcast "This facility is now under the command of the Earth Defence Force. Drop your weapons immediately. All armed personnel will be shot on sight."
Red Faction II
In Red Faction II, the nanotechnology developed by Capek was claimed by the EDF. With this advanced level of military technology, the EDF reorganized the Ultor Corporation with a particular focus on enhanced supersoldiers and suitable weaponry.
Red Faction: Guerrilla
At the end of the first Red Faction the Earth Defense Force came in and helped the Red Faction beat Ultor and rid Mars of them. Instead of leaving once the job was done the EDF stayed on Mars and over the 50 years they have gone from being the liberators of Mars to the new oppressors. In fact they are worse than Ultor. The people of Mars do not have any rights, are beaten in the streets by EDF officers, and live in complete misery. Finally having enough of the oppression, once again the miners have called up the name of Red Faction and have started a guerrilla movement against the EDF to push them off the planet and liberate the people. The EDF is the main antagonist in Red Faction: Guerrilla.
After Red Faction: Guerrilla
It is unknown what is to become of the EDF after the events of Red Faction: Guerrilla.