Edward Greenspan has taken Louise Arbour, the United Nations High Commissioner for Human Rights, to task for suggesting that some of Israel's actions in Lebanon could give rise to individual criminal responsibility. With all respect, she was right.
In his essay in The Globe and Mail on Thursday, Mr. Greenspan conflated two separate sets of international rules. The first, which includes the right of self-defence, governs the recourse to force. The second, known as "international humanitarian law," limits the way belligerents may behave once a conflict has begun.
The UN Charter prohibits the use of force against the "territorial integrity or political independence" of nation-states. Self-defence is an exception to this general prohibition, and exceptions are always narrowly construed.
Until recently, self-defence was available only in response to an attack by another state's armed forces. After 9/11 and the intervention in Afghanistan, which was supported by almost all countries, self-defence now extends, in some circumstances, to the use of force against state sponsors of terrorism.
It does not expose countries to military action whenever terrorists operate from their territory. Consider the position of Germany after 9/11: Although Hamburg had unwittingly harboured several of the terrorists, a military response on German soil would not have been justified.
"But the Lebanese government is responsible for the actions of Hezbollah," goes the argument. And yet the Lebanese government is democratically elected and pro-Western. As U.S. President George W. Bush and British Prime Minister Tony Blair have recognized, it needs our help, not unsubstantiated allegations of involvement in Hezbollah attacks.
It would make more sense to argue that Israel is entitled to act in southern Lebanon because the writ of the Lebanese government does not run that far. The problem with this argument, however, is that it cannot justify strikes elsewhere, including on Beirut international airport, roads and bridges, and even a lighthouse.
Attacks on non-Hezbollah targets also breach the centuries' old criteria for self-defence, of necessity and proportionality. Remember, they came in response to the capture of two Israeli soldiers and the killing of eight others by Hezbollah militants.
Yes, thousands of rockets have been launched at Israel. But Israel's existence is secure, at least for the foreseeable future. To put matters in perspective, more than two dozen Israeli civilians have lost their lives in this conflict. So, too, have eight Lebanese Canadians.
To her credit, Ms. Arbour restricted her comments to international humanitarian law. In doing so, she was acting entirely within her mandate as UN High Commissioner for Human Rights, for these rules exist to prevent unnecessary human suffering.
The rules of international humanitarian law are set out in the 1949 Geneva Conventions, which Israel ratified in 1951. For the most part, they apply to Hezbollah as customary international law.
The direct targeting of civilians is categorically prohibited, including acts or threats of violence intended to spread terror or impose collective punishment. Indiscriminate attacks are also proscribed.
Above all, individual targets may only be selected if the direct military advantage anticipated from the strike exceeds the expected harm to civilians or civilian objects. For this reason, Hezbollah's rocket attacks, which have been aimed at the general vicinity of Israeli cities and towns rather than specific military targets, are illegal.
But so, too, are some of Israel's attacks.
Of the more than 700 Lebanese civilians killed, some were struck by Israeli missiles after they followed Israeli instructions to leave their homes and villages. Others were hit because blasted roads, bridges and gas stations had made it impossible for them to flee.
More civilians died when bombs were dropped in densely populated neighbourhoods where the military advantage would have to be enormous to exceed the civilian harm. Even more are dying now as hospitals, water filtration plants and sewage treatment facilities struggle with power shortages.
In no circumstance may attacks on civilians or civilian infrastructure be justified by similar violations on the other side. The horrors of Qana, where more than two dozen Lebanese civilians died in a single precision air strike, cannot be balanced by lost Israeli lives.
And don't forget the four UN observers who were struck by a precision-guided bomb in a highly visible, long-established post located on a barren hilltop — after Israeli forces had been warned repeatedly that their projectiles were falling perilously close by. If the killing of the observers was deliberate, it, too, would constitute a violation of international humanitarian law.
As Ms. Arbour indicated, violations of international humanitarian law constitute war crimes, which are subject to universal jurisdiction in the sense that the perpetrators may be prosecuted in any country's domestic courts.
Mr. Greenspan, an acclaimed domestic criminal defence lawyer, might want to brush up on his international law. His services might soon be required.
Michael Byers holds the Canada Research Chair in Global Politics and International Law at UBC. He is the author of War Law: Understanding International Law and Armed Conflict. In April of 2004, he was a visiting professor of law at the University of Tel Aviv.