"How can a war be fought for Oil by the machines that run on it? Of course, it's the civilians who are victims to the shortages, not the military."
Wars may occur in regions with
- high Militancy
- low Stability
- very high unemployment
- persistantly low contentment
- low HDI or any combination of those factors.
Regardless for how responsible the GEO is for either causing instability or failing to keep the peace, Support will rapidly fall regardless. Agents operating in a Warring Region are very likely to go "missing" in the confusion and unless stability is re-established then the GEO is on borrowed time before the Region outright bans them.
For the most part, wars are easily preventable through the use of cards that promote Stability. Even if a war does break out, it will automatically end if the GEO declares Martial Law (or through raising contentment high enough for the war to end on its own).
If the GEO is banned and War has broken out, the Region will still periodically "open their doors" to the GEO returing however given how chaotic the Region will most likely be, swift action to end the conflict must be taken or the Region will simply end up banning the GEO within a few turns.
One overlooked problem of wars is that they cause famine, as the conflict destroys infrastructure and redirect food aid. This tends to lead to a cycle of War where if left ignored, the Region will constantly have wars over food which will lower Agricultural production, kill civilians and make any lasting cease-fire impossible without GEO intervention.
If there is no GEO intervention, wars can either end on their own (likely to start again within a few years), or erupt into a full-scale nuclear war if the Region possesses 4th Generation Nuclear. There is a chance that a regional nuclear war will escalate to a Global Thermonuclear War, causing the game to end. Otherwise, the regional nuclear war will quickly end, as most of the combatants will be killed off.
The game takes a minimalistic and cynical approach to wars; combatants are rarely detailed or summarized (and when they are portrayed, are treated as entities who intentionally or unintentionally cause famines), and the political leaders that are presumably leading these rebel and government forces are more interested in blaming each other for starting the war in the first place than aiming to prevent their own citizens from dying.
Due to the unified nature of Regions in the game, wars are also periodically referred to as civil wars.