Law includes a system of authorized coercion in which force is used to maintain and enhance public order objectives and in which unauthorized coercions are prohibited. Thus law and coercion are not dialectical opposites. On the contrary, formal legal arrangements are not made when there is a spontaneous social uniformity; then there is no need for law. Law is made when there is disagreement; the more effective members of the group concerned impose their vision of common interest through the instrument of law with its program of sanctions. Law acknowledges the utility and the inescapability of the use of coercion in social processes, but seeks to organize, monopolize, and economize it.
W. M. Reisman,
Criteria for the Lawful Use of Force in International Law,
Yale J. Int'l L.
Available at: http://digitalcommons.law.yale.edu/yjil/vol10/iss2/5