According to the U.N. High-Level Panel on Threats, Challenges and Change, "The maintenance of world peace and security depends importantly on there be-- ing a common global understanding, and acceptance, of when the application of force is both legal and legitimate."
The provision of security imposes two requirements: Those not authorized to use force should renounce its use and threat in their social relations, while the authorized agents of any community with the monopoly on the legitimate use of violence must have the capacity and will to use force when required.
For it to be efficient, any international enforcement action must be legitimate -- in conformity with international law and consistent with the U.N. Charter. For it to be effective, it must match action to resources and be based on a unity of purpose and action in the international community and avoid fracturing the existing consensus. For it to be equitable, it must reconcile or, at the very least, balance competing interests among the many constituencies that make up the international community and avoid favoring the interests and viewpoints of one over the others.