Throughout world history, the principal threat to international peace and security has been “war”—the threat that the League of Nations, the Kellogg-Briand Pact, and the United Nations sought, but failed, to prevent.

Traditionally, war has been declared and fought on a mass scale, waged by soldiers fighting for states in organized armies. In the traditional understanding of war, it was possible to attack a nation only by first destroying the army that protected it. Civilians were thus largely insulated from conflict, physically separated from danger by the armies that stood between them and their enemies. Prior to the rise of airpower and the advent of weapons of mass destruction, international law did not have to address the security of the civilian populations themselves. Legal regimes therefore proscribed war generally and only protected civilians in occupied territories. “Civilian” security was generally a matter of domestic law.

While interstate warfare has declined in recent decades, civil conflict arising from ethnic, religious, and nationalist strife is on the rise. And as the events of September 11 demonstrated in the starkest terms, international violence is no longer limited to war fought between states, whether declared or undeclared. Individuals can murder thousands and potentially millions of other individuals across national borders without ever encountering an army. The physical space between combatant states as patrolled by soldiers, sailors, and pilots no longer serves as a protective buffer to safeguard civilians. National armies and state-supported terrorism are still important, but international rules addressing only organized state violence are more appropriate for past wars than for wars to come.

To address this new generation of threats, international law must move beyond general prohibitions on war and develop a regime to protect civilian lives. We must embrace and elevate the principle of civilian inviolability to an absolute prohibition on the deliberate targeting or killing of civilians in armed conflict of any kind, by states or individuals, for any purpose. This principle must become a foundational principle of the international order, equivalent to and parallel with the prohibition on interstate war in Article 2(4) of the UN Charter.

When the framers of the UN Charter adopted the prohibition on the use of force in interstate relations in Article 2(4), they were pulling together a number of strands of existing law, similar to the situation today. The principle of civilian inviolability has been strengthened and developed in three distinct bodies of international law—the law of war, international criminal law, and the law of terrorism. The law of war regulates the conduct of combat, with an emphasis on protecting civilians from violent conflict. International criminal law has grown from its roots in Nuremberg to hold individuals accountable for international crimes. The law of terrorism has developed in an effort to prohibit attacks by non-state actors and state sponsorship of these attacks.

These three bodies of law are deeply rooted in the existing international order and are supported by generally effective enforcement mechanisms. Collectively they offer a powerful new logic to address and possibly prevent violent conflict in the next century. The protection of civilians must become more than a specialized doctrine applicable in specific areas of the law. “Civilians” are individuals who do not choose to engage in armed conflict, who seek only to go about their lives and participate in their communities. They are not cannon fodder, not tools to be used as means to any end. They must be free from violence, whether from their own governments, marauding armies, suicide bombers, or hijacked planes.

Under the law of war the principle of civilian inviolability is typically referred to as “noncombatant immunity.” The change in terminology that we propose, as well as the elevation of this principle to a foundational principle of international order next to Article 2(4), is telling. “Noncombatant” implies individuals trying to stay clear of the violence swirling around them. “Civilian” means members of civil society, in every nation around the world and increasingly across borders. It is the birthright of all civilians, as all humans who choose not to take up arms, to be free from violence, to be free to live their lives in dignity and peace. The move from “noncombatant immunity” to “civilian inviolability” is thus a move from the law of war to the law of peace.

The Law of War

The law of war has a long history both in formal agreements and in the practice of states. This body of law provides the foundations for the principle of civilian inviolability. As early as the Hague Conventions of 1907, international treaties restricted the conduct of warfare in order to protect civilians from armed conflict. These early regulations were limited, prohibiting only “the killing and wounding treacherously” of noncombatants and the bombardment of undefended towns. Killing civilians for killing’s sake was outlawed, but killing civilians for military advantage remained permissible. In 1938 the League of Nations added its voice, finding that the intentional bombing of civilians “was illegal.”

It was not, however, until the 1949 Geneva Conventions that an overarching regime to protect civilians was codified. The Fourth Geneva Convention of 1949 was specifically drafted to protect civilians in international armed conflicts. The convention regulates the treatment of civilians in occupied territories and forbids “grave breaches,” including the “willful killing, torture or inhuman treatment” of civilians. The Geneva Conventions place affirmative duties on states to suppress such breaches and to search for and extradite or prosecute violators.

While the grave breaches provisions only apply in international armed conflicts, Article 3, common to all four Geneva Conventions, applies to any armed conflict, international or internal. Common Article 3 is weaker in form than the grave breaches provisions; it does not impose duties to suppress or prosecute. Nonetheless, Common Article 3 forbids “violence to life and person,” and “outrages upon personal dignity” against “persons taking no part in the hostilities.” The 165 states-parties to the Geneva Conventions thus created the first global regime to protect civilians from willful killing in the course of armed conflict.

The next significant step forward in the development of the principle of civilian inviolability was the adoption of the 1977 Additional Protocols to the Geneva Conventions. Additional Protocol I, applicable in international armed conflicts, establishes a basic rule that all parties must “distinguish between the civilian population and combatants… and accordingly shall direct their operations only against military objectives.” Likewise, Additional Protocol I requires that “the civilian population as such, as well as individual civilians, shall not be the object of attack.” Additional Protocol II, which applies in all armed conflicts, is less specific, but nonetheless guarantees that “the civilian population… shall enjoy general protection against the dangers arising from military operations.” The foundations of the principle of civilian inviolability were thus established.