02/07/2009 05:12 am ET Updated May 25, 2011

Proportionality and Disproportionality: A Guide to Arguments about Gaza

A ceasefire between Israel and Hamas seems imminent, although how long it will last is anyone's guess. One thing is fairly certain: even as the guns fall silent the charges and counter-charges of violations of international law will continue. Already the airwaves are full of talk that Israel's "disproportionate" response is a flagrant violation of international law. The Palestinian Authority has claimed, in addition, that Israel's actions constitute "aggression against the Palestinian people," and a "crime against humanity. "(See CNN"s Jim Clancy's interview with the Palestinian Authority's Ambassador to the United Nations, Riyan Mansour, January 3, 2009). In this climate, it might be wise to take a deep breath and consider international law not as a propaganda tool but as a guide to reasoned behavior. Here is what such an approach reveals:

1. In international law, the concepts of proportionality and necessity are intertwined. If the action is not necessary for a legitimate military objective (security against armed attack), then it is inherently disproportionate. Was Israel's response to more than a thousand rocket attacks by Hamas, which were bound to continue upon Hamas' refusal to renew the ceasefire with Israel, a legitimate military objective?

In answering this question, context is all important. Hamas had declared that its objective in sponsoring suicide bombings in Israel, and more recently in the indiscriminate use of rockets against Israeli population centers, was nothing less than the destruction of the state of Israel. Some might dismiss this aim as not worthy of being taken seriously. But those who would dismiss Hamas' stated objectives do not give the organization sufficient credit for its commitments and abilities. Hamas does not operate in a vacuum. It is supported ideologically and militarily, if not directed, by the mullahs who rule Iran. They have sworn that the destruction of Israel is a top priority. The international community has recognized that they are developing nuclear weapons to give them that capability. Iran's proxy troops are Hezbollah in Lebanon to the north of Israel, with a capacity to fire tens of thousands of Iranian manufactured rockets wherever it chooses; and Hamas in Gaza to Israel's south, able to direct sufficient indiscriminate firepower to intimidate a million Israeli citizens into living lives that vacillate between air raid sirens and the rush to shelters. In this context, an Israeli military response to Hamas' decision to let the rockets rain again was clearly justifiable.

2. The fundamental aim of international humanitarian law is to draw a distinction between combatants and non-combatants. In its authoritative ruling, Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons (1996), the International Court of Justice held that: "states must never make civilians the object of attack and must consequently, never use weapons that are incapable of distinguishing between civilian and military targets." Moreover, it prohibited employment of weapons for "uselessly aggravating their [civilian] suffering."

Applying these principles, did Hamas needlessly cause large scale civilian suffering? Did Israel needlessly cause such suffering?

Clearly, Hamas' attacks intentionally drew no distinction between combatants and non-combatants. Indeed, Hamas deliberately targeted Israeli civilians. By various accounts, Hamas also deliberately placed and fired those weapons from schools and public areas, thus endangering Palestinian lives. Accordingly, the use of such weapons by Hamas was a war crime. It is immaterial whether Hamas is a state or non-state: either can be guilty of war crimes. Nor, of course, is it any defense to the firing of those weapons to contend that they were undertaken in response to Israel's economic "boycott" of Gaza. First, there is no international law requiring one state to open up its borders for commerce with another state or entity. Secondly, by Hamas' own admission, it is in a state of war with Israel and economic boycotts are the least offensive measure one can take in a state of war.

With regard to Israel, were it demonstrated that particular Israeli air strikes "uselessly" aggravated Palestinian civilian suffering, and that the commanding officers knew or should have known this, they would be subject to prosecution for war crimes. But the particular should not be confused with the general. It is irresponsible to speak of "aggression" in the context of self defense against rocket attacks, or to contend that such a response is a "crime against humanity."

3. International law requires that peaceful means must be exhausted before resort to force. Assuming, although highly questionable, that Hamas merely sought an end to Israel's occupation of the West Bank rather than Israel's destruction; might Israel not have avoided Hamas' termination of the ceasefire if Israel had eased up on its territorial demands in order to resolve Israeli-Palestinian differences? But neither Israel, nor the Palestinian Authority, was willing to make important concessions. Moreover, all serious observers knew that a massive Israeli strike would inevitably follow the continuation of rocket attacks. Thus, even looking at Hamas' actions in the most charitable light, peace is not achieved through the barrel of a gun or the plume of a fired missile.

4. Finally, international law does not require the least destructive military response, only the response least destructive to civilians. As the war came, Israel was left with the daunting responsibility of protecting its own citizens while avoiding useless Palestinian suffering. Could this have been accomplished by a less destructive alternative to Israel's bombing in the middle of Gaza- i.e. by cutting of Gaza's access to weapons in the south of Gaza by making that border impenetrable? This is a question of tactics and means and until the smoke of fire clears we will never know the answer as to whether the building of large underground barriers (in Egypt with Egypt's permission) was a viable alternative. Regardless, it would be incumbent upon anyone arguing that Israeli military and political commanders knew of viable alternatives (short of surrender) to stopping the rocket attacks to demonstrate that, in fact, such alternatives existed.

Allan Gerson is the author of Israel, The West Bank and International Law. He served as counsel to the US Delegation to the United Nations and currently practices law in Washington, D.C.