Inevitably, some use their position for personal gain against a civilian population too terrified to resist.[24][25] However, inconsistencies in academy standards led to stormtroopers of varying combat skill and ability.[26] After subduing any remaining Separatist holdouts left over from the Clone Wars, stormtroopers primarily serve as an internal security and peacekeeping force until the Galactic Civil War where they start to engage the Rebel Alliance in large-scale battles.[24][25]