When Does the Security Council Authorize Armed Force?

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.

"Breaches of the peace" of the sort that give rise to the possibility of Security Council action occur more or less constantly.  The clearest case occurs when one nation attacks another, and the nation attacked lacks the military wherewithal to repel the attack.  The UN response to the North Korean invasion of South Korea is a leading example where the Security Council authorized force in response.  Another was the authorization for force to repel Iraq's invasion of Kuwait in what became the first Gulf War.

Yet given the structure of the Security Council, authorizations for force are rare.  It occurred with respect to the Korean Peninsula because, at the time, Taiwan held the Chinese permanent seat on the Security Council and the Soviet Union was temporarily boycotting the UN.  For the rest of the Cold War, Security Council authorization of force for any substantial conflict was effectively impossible.  Even in the post-Cold War era, China and Russia have been quite reluctant to authorize military action, and there have also been fissures among the permanent members from the West (such as French opposition to the Bush 2 Administration's efforts to obtain authorization for the 2003 invasion of Iraq).

One can legitimately question whether the permanent members should have veto power, but it has some considerable sense behind it: In order to avoid the spread of military conflict to involve powerful (nuclear-armed) militaries, the thinking goes, it is important that any authorized use of force not occur against the will of one or more such powers.  One can quibble with the  membership: Why France but not India?  How about Brazil?  Pakistan?  Etc.  But the concept makes some sense.

As a consequence of the structure of the Security Council, a breach of the peace is a necessary but not a sufficient condition for force to be authorized.  The target of the force also must not be a client or otherwise protected State of one of the permanent members--and enough temporary members must be brought on board to get a majority in the Security Council.  Russia's historical relationship with Serbia and Serbs more broadly may partly explain why the UN was largely ineffective in its efforts to stop the violence in the Balkans in the 1990s.

Even absent an identifiable external protector, an aggressor can escape intervention if the great powers simply don't care enough to mobilize.  The Rwandan genocide of the 1990s is the clearest recent example of this phenomenon, but there are many other examples as well.

Given all of this, when does the Security Council vote to intervene? Looking at the salient examples, it appears that most or all of the following conditions must be satisfied:

1) A very serious act of aggression against either another state or an internal population group;

2) No protection for the aggressor from one of the permanent members of the Security Council;

3) At least one country, preferably a Security Council permanent member, that champions the intervention;

4) At least a fair prospect that the type of military intervention that can be stomached politically will have the sought-after strategic impact;


5) Support for the action from the major regional powers.

In Monday's post, I asked rhetorically why force was authorized for Libya but not Bahrain, Yemen
Publish Post, or Syria.  Looking at my list of factors, we can see that Bahrain and Yemen are more or less protected by the U.S. and Saudi Arabia, a key regional player.  Syria does not have an obvious great-power protector, but effective military action against the Assad regime would require an effort on a scale that probably no permanent member wants to stomach right now, and could draw Iran into a conflict. As for Libya, it appears that support from the regional powers may have been determined most by personal animosity towards Qadaffi.

Of course, it is nuts to have such crucial questions decided based on personal relationships.  However, given the strong element of realpolitick that the Security Council's structure introduces into the equation, such personal factors are probably inevitable.