Public hostility is higly volatile and can be swayed by friendly or enemy actions. Maintaining good relations with civilians can greatly improve the effectiveness of friendly troops occupying a city. It is often difficult to know that you have done something to anger civilians until they react.

There are varying rules of engagement and opponents who fight your rules of engagement. Asymmetric opponents can gain advantages by using different fundamental tactics. This violates assumptions and challenges mental models.

Local groups fighting amongst each other can have ancillary negative effects. Aggression can shift or increase the danger to friendly operations of an otherwise safe area.