Stability is the main concept behind gameplay in Overthrow and applies to almost everything you do. At the start of the game, most towns will have a state of stability above 50% with a few in the south under. On your map, a red circle starts to appear below 50% and becomes completely opaque at 0%.
While moving around Tanoa you will be notified when you enter a new town and what the current stability is. To check any town go to "Town Info" in your Main Menu after pressing 'Y'
Stability goes down when the town is not protected and/or NATO soldiers are dying there. It will also go down if the closest radio tower is not controlled by the same faction.
Stability goes up when the town is well-protected and criminal elements are being taken care of. It will also go up if the closest radio tower is controlled by the same faction. Building police stations and stationing police men raises stability over time.
When stability drops below 10% NATO will put the town into a state of "anarchy" and deploy a QRF to restore order. (No QRF when the population below 50) If this operation is not successful then NATO will abandon it (for now). Towns in a state of anarchy will also attract a high number of criminal gangs. During this state taxes are still paid to the resistance but due to the difficulty obtaining them it will be much less. The town will stay in a state of "anarchy" after abandonment until stability goes back over 50%. Some taxes will be paid to the resistance in this state, but not as many as when the town is. Resistance players can place buildings in towns that are in anarchy (e.g. police stations to restore stability).
A town that is abandoned by NATO and over 50% stability is considered under the control of the resistance and liberated. Taxes from the public there will be paid to the resistance and distributed evenly amongst all online players.