Our international system rests on two pillars: states are sovereign, and they shall not, for the most part, attack each other. Both of these are reflected in the U.N. charter which recognizes two exceptions: an attack in accordance with U.N. Security Council resolution or in defense of one’s self or collective. The U.S. is now faced with either abiding by these laws or abandoning them for a possible unlawful intervention in Syria. For all its disregard for law, including the recent use of chemical weapons, the Syrian regime has not given up its own sovereignty. As a matter of international law the conflict continues to be an internal despite the violent spill over into Turkey and Lebanon.
The first exception to the rule covers any intervention supported by the Security Council. The U.S. had such a mandate in Libya, Afghanistan, Somalia and the most recent Gulf War. Due to a likely veto from Russia and China that deals with any Syrian intervention there is little possibility for U.N. sanction.
The second exception applies to defense of self or the collective. Under this ruling Jordan, Turkey, Israel, Iraq or Lebanon could respond as could their allies in NATO. Legally this is a very grey area. Despite the occasional skirmish on Turkish or Israeli borders this may not have created a justification for war.
Some may argue that states have a right to self-defense in the form of a preemptive attack. However, this theory has a troubled past not the least of which is due to the U.S. justification of the Iraq war, not to mention it relies heavily on proof of imminent threat and intent. There doesn’t seem to be any sign of intent from the Assad regime and these are historically hard to prove.
The U.S. will likely compile an argument based on the chemical weapons usage and horrors taken place within Syria, of which there are many, and argue the adverse impacts on the region. As in the case of Kosovo, this argument produces a war that is unlawful, but justifiable nonetheless. This argument is made even more murky by the fact that Syria has never signed the Chemical Weapons Convention, and thus may not be held to a law they never signed.
The Obama administration must also wrestle with U.S. law as well as international. The Constitution divides power between the Executive and the Congress which has the ability to declare war, raise taxes to support war and set the rules for war. The Justice Department decided in 2011 that the President could launch attacks into Libya as long as “such use of force was in national interest” and the duration “would not trigger Congressional approval.” The argument that Syria now threatens regional stability is certainly plausible but may not be enough to sway Congress.
When we feel passionate about a conflict it is easy to dismiss these laws as unnecessary constraints on American power. However, international law has a value more than its codification of normative values. The slope between war and peace can be very slippery and the treaties, laws and institutions act as road signs and brakes on that slope allowing us weigh the enormous costs of war. By following international law we could slow the slide to war and build a legal, moral and truly international force.