Was the US-led attack on Iraq justified? The question comes from all corners of the globe, and answers are varied. Our collective response should be to cooperate in thoughtfully examining the practical constraints and legal limits to military intervention. The issue is not black-and-white, but multifaceted, and only by addressing it head-on can our international community hope to reach a consensus that will cement genuine autonomous international security for all.
As a cornerstone of international law for more than 350 years, the principle of non-intervention protected a range of different interests. Originally, it protected the sovereign prerogatives of the crowned heads who ruled Europe. While monarchies are not totally obsolete, the principle of non-intervention is now more likely to protect the democratic systems of self-determination and popular sovereignty. It has always helped to promote international peace and stability by discouraging the use of force against the territorial sovereignty and political independence of states. Today, both the reasons for the principle and the necessary exceptions to it can best be understood in terms of human rights.
When the current system of international law began to develop in Europe, it was built upon new rules of sovereignty and non-intervention. This system, unlike that of the hierarchical Holy Roman Empire that preceded it, is founded on the idea that each state is independent and has the same set of sovereign rights. Those who took responsibility for order and justice within the territorially-based state had all the rights of sovereignty under international law, including the exclusive right to make and enforce laws within that state. The principle of non-intervention promotes the peaceful coexistence of autonomous sovereign states by banning each of them from the use of force within the territory of the others.
International law recognizes each state's rights of sovereignty and territorial integrity but cannot guarantee that other states will respect those rights. The international legal system is weak in that it lacks the centralized legislative and judicial organs and coercive executive powers to enforce the rule of law at the national level. Due to this weakness, states must often rely upon self-help to protect their rights under international law. The classic form of self-help is self-defense.
The Right of Self-Defense
The most notable exception to the general principle of non-intervention stems from the right of self-defense. Customary international law develops when the behavior of states over time indicates they have accepted a rule of law. Under that law, two essential conditions limit the right of states to use force in self-defense. First, the use of force must be necessary. In an 1841 letter to British Minister of Foreign Affairs Henry Stephen Fox, US Secretary of State Daniel Webster described this requirement as "a necessity of self-defense, instant, overwhelming, leaving no choice of means, and no moment for deliberation." The second requirement is that the acts of self-defense must be proportionate to the threat. This customary standard does not condition the right on a prior armed attack.
The rules of international law are built upon the premise that states, like people, have a natural right to defend themselves against the imminent threat of harm. Article 51 of the UN Charter states that "[n]othing in the present Charter shall impair the inherent right of individual or collective self-defense if an armed attack occurs against a Member of the United Nations." To the extent that self-defense is an inherent right, the use of force in preemptive self-defense could be justified even without a prior armed attack. This topic raises difficult issues of how to define and apply workable legal standards in matters affecting national security.
Intervention on Behalf of Human Rights
Proponents see humanitarian intervention as a fundamental exception to the principle of non-intervention. …