By Mike Dorf
On Monday I parsed the text of the U.N. Security Council Resolution authorizing force to protect Libyan civilians and to enforce a no-fly zone over Libya. I promised two follow-ups on the U.N. Security Council decision-making process, but then yesterday I pre-empted one of those posts to address the domestic constitutionality of President Obama's acting without prior congressional approval. Today I return to my original plan, consolidating the two follow-ups into this one discussion.
Let's begin with the basics. Under Article 51 of the U.N. Charter, the unilateral or collective use of force is permitted to repel an armed attack. (This was the U.S. justification for going to war in Afghanistan following 9/11.) Defensive war, in other words, can be waged without prior approval from the U.N. Security Council. The Security Council can also authorize the use of international armed force pursuant to Articles 39-49 in order to combat "any threat to the peace, breach of the peace, or act of aggression," where measures short of force have failed. That was the power the Security Council exercised when it authorized force to be used in Libya. My question for today is how does the Security Council decide when this power should be exercised.