“Disproportionality” is the new buzz word in response to Israel’s military action. Jimmy Carter espoused “disproportionality” to a German journalist during Israel’s 2006 war against Hezbollah. Unable to counter Israel’s right to self-defense, among some writers, “disproportionality” is often preceded by “Although Israel has the right to self-defense…”

“Disproportionality” is invoked as a moral claim, asserting that Israel has fallen short. It is in fact a moral retreat.

Civilized society has adopted basic moral principles about killing. As a rabbi, I am justifiably proud to state that they appeared in the Torah, a.k.a., The Five Books of Moses, 3,000 or more years ago.

1. The murder of any human being is among the worst sins against God and among the worst sins and crimes against the person and the society. Thus, Torah legislates that murder — when due process is followed — is punishable by death; financial recompense is prohibited. Similarly, in modern civilized society, murder is punishable by the maximum penalty.

2. The unintentional killing of a human being is not murder, but manslaughter. There are two cases of manslaughter: (a) one which could have been reasonably prevented and is criminally punishable — though to a lesser degree than the punishment for murder — or (b) one which is reasonably unforeseen, and although sad and tragic, is not criminal.

3. The threat of being intentionally killed justifies, and in our teaching, obligates a preventative response, even if the threat is to another person. If other means are or would be insufficient or ineffective to prevent the murder, killing the potential killer is warranted and even mandated.

These three principles apply in war, but the increase in numbers increases the magnitude and the tragedy:

1. A nation is morally culpable for murdering innocents, including soldiers that surrender, as they are no longer a threatening combatant.

2. Unforeseen unintentional killings are tragic, not criminal. Indeed, occasionally “friendly fire” (an unsatisfactory euphemism) occurs, that is, one’s own soldiers will unintentionally kill their own, let alone those of the enemy. Every reasonable effort should be made to avoid killing civilians.

3. And when one’s civilians are attacked or the enemy threatens to continue to do so, a civilized society is morally and duty-bound to respond with force, even if unintentional killing will occur. And if the government does not do so, the people of the nation legitimately would oust them and install a government that will.

“Disproportionality,” is a muddled claim that the concern for numbers is morally superior to the aforementioned three principles. The argument is so patently morally inferior, that to embrace it would cause far more death as it would embolden murderers and leave innocents vulnerable. The claim is so weak that civilized nations would discard it after its failure became apparent.

Although some myopically focus on the occasional rogue, Israel, like the United States, but unlike many of our enemies, makes every effort and succeeds at avoiding targeting civilians; the main exception is when the enemy attacks from civilian areas. To refrain from responding would be to provide sanctuary and legitimize the ploy.

Like the United States, but unlike many of our enemies, Israel will review its actions, and if there is credible evidence that officers and soldiers targeted civilians they will be prosecuted as criminals. We did so regarding the massacre in My Lai, Vietnam, and Israel did so in the early 1980s when it held then-General Ariel Sharon, officially culpable, not for ordering the killing of Palestinians in Sabra and Shatillah refugee camps in Lebanon, but for allowing Christian Phalange to enter the area. The committee concluded that the general could have and should have anticipated violence. If Israel was willing to investigate and hold responsible an Israeli general for indirect responsibility, one can have confidence that it will similarly do so if there are credible allegations of murder.

We should deeply regret all loss of life — even our enemies. At our Pesach seder each year Jews explicitly articulate this message as we spill drops of wine from our cups when reciting the Ten Plagues.

We must, as Americans and as Jews, expect our military to avoid civilian killings as much as possible. But to subordinate basic civilized principles to the emotion of “proportionality” would be a moral failure, an inconsistent application, and an unsustainable policy resulting in even more death.

May we strive for and attain genuine peace.

Rabbi Seth D. Gordon is the rabbi of Traditional Congregation in Creve Coeur. He is on the national board of the UTJ (Union for Traditional Judaism in Teaneck, N.J.).