3-34. DDR, encompassing the processes that safely transitions combatants back to civilian life, and SSR, involving the reconstitution and professionalization of security institutions and actors, are interdependent and mutually reinforcing. Working in tandem, they can enable countries emerging from conflict to provide for their own security and uphold the rule of law, an essential precondition of sustainable development and part of the exit strategy for costly peacekeeping missions. As such, politically, they rise or fall together.