SSR after war, that is institutional change in the police, military and judiciary, stands at the core of peacebuilding strategies. At the same time these reforms are highly contentious as they influence and change existing power relations. Armed actors (state as well as non-state) lose their dominance due to disarmament, reduction in numbers, or civilian and democratic control. External actors tend to favour stability, while civil society tends to advocate for fundamental change such as accountability of security actors. Under a broader perspective of peace beyond the mere absence of war, difficult choices have to be made early on in peace processes. The paper outlines a theoretical model first, illustrating it with some evidence from Uganda and El Salvador.