Intentionally targeting civilians and proportionality (in general and in Israel and Gaza)
The standard version of the doctrine of double effect (DDE) posits that it is sometimes permissible to intentionally commit an act that has the foreseeable consequence of causing serious harm (including the death of innocent people), so long as that harm is an incidental effect rather than the goal of the act and is proportionate to the act's benefit. Standard DDE has been offered as a basis for permitting a lethal dose of palliative medication where the doctor intends to alleviate a terminal patient's pain, with death as a foreseen side effect. More directly relevant to current events, DDE operates in the international humanitarian law of war, which forbids targeting civilians but permits targeting combatants even though civilian casualties are a foreseeable collateral consequence, so long as the attacker attempts to minimize civilian casualties and the foreseeable civilian casualties are proportionate to the military advantage to be gained by attacking the combatants.
In A New and Improved Doctrine of Double Effect: Not Just for Trolleys, Professor Sherry Colb offered a reconceptualization of the doctrine of double effect. Crediting various critiques of DDE that call into question both the feasibility and wisdom of sharply distinguishing between directly intended consequences and foreseeable but not directly intended consequences, she proposed an objective rather than subjective reconceptualized DDE (RDDE). As she summarized RDDE, it "allows an action if one can plausibly identify a permissible intention that could explain that action and any resulting harm is proportionate to the expected benefit." RDDE, she argued, has explanatory power across a broad range of the legal landscape, including, for example, the law of evidence, where testimony may be admissible for one purpose but not another (so long as it is not unduly prejudicial with respect to the forbidden purpose), regardless of the subjective goal of the party or attorney offering the testimony.
A New and Improved is, in my view, powerful and persuasive, which is not to say that it is wholly unproblematic. Consider its application to the law of war. Professor Colb acknowledged that under RDDE, if an attack on a military target would result in only proportionate civilian casualties and the military official ordering the attack has taken available measures to minimize those casualties "(e.g., by leafletting in advance of the bombing"), the attack is permissible even if that official secretly "like[s] the idea of killing civilians . . . because such killings demoralize" the enemy population "and can turn them against the war, much in the way that terrorists aim to affect public opinion."
In her paper and oral presentation at last month's Symposium in honor of Professor Colb, Professor Sheri Johnson acknowledged the power of RDDE in a range of areas, including the law of evidence, but also pushed back against the proposition that subjective intent shouldn't matter. Although Professor Johnson mostly focused on cases involving race discrimination, her core point--for which she relied in part on some of Professor Colb's own other works (e.g., this one)--also applies to the military context. Surely the military officer who orders the bombing with the hidden goal of killing civilians is worse than the one who does so while regretting civilian casualties, Professor Johnson said.
Were Professor Colb still with us, I suspect that she might respond that in the wartime example, the secret pleasure the military officer takes in killing civilians makes him a bad person and is thus relevant to an assessment of his character, but that an actor's character is not always relevant to an assessment of his conduct. (See, e.g., this essay by Professor Colb in the 1999 Stanford Law Review). I am not sure whether that response or some other one adequately parries Professor Johnson's critique. I would note that under either Professor Colb's or Professor Johnson's view, we can judge the attacker who gladly kills civilians as worse than the one who kills them knowingly but regrettably.
In other words, we can grant that it is worse -- either as a matter of character, conduct, or both -- to intentionally target civilians than to harm them as a collateral consequence of otherwise justified military action. But does it follow that it should be permissible to take actions that have the foreseeable consequence of causing numerous civilian casualties? Intentional murder (which is defined as intentional or knowing murder) is worse than reckless homicide; and other things being equal, a person who commits intentional murders exhibits a worse character than one who commits "only" reckless homicides; but we can still say that reckless homicide and the person who commits reckless homicide are bad, even if they are not as bad as murder and murderers.
Which brings us to the present moment. What Hamas did by murdering civilians was grotesque and plainly illegal. People who argue or imply that it is somehow justified by Israel's occupation of the West Bank, its blockade of Gaza, or its very existence are appropriately subject to opprobrium. They should not be taken seriously as an intellectual or moral matter.
Accordingly, I shall focus my legal and moral analysis on Israel's retaliation. We can stipulate that Israel's warmaking is not as bad (as a matter of conduct or character) as what Hamas has done, but that doesn't mean it is necessarily justified.
Is Israel violating the laws of war? Maybe. Even putting aside the question whether the "total siege" can be said to target Hamas in particular rather than all of Gaza, there are real questions about minimization and proportionality. Israel's warning to evacuate will result in fewer civilian casualties than would likely have occurred without any warning, but given the scale of suffering the civilian population of Gaza is enduring, it is possible to conclude that the response overall is disproportionate and thus unlawful.
One could argue for the contrary conclusion--i.e., for proportionality--on the ground that Israel is doing all it reasonably can do to minimize civilian casualties because Hamas deliberately hides among the civilian population, making it impossible to target Hamas without leading to very large numbers of civilian casualties. Yet one might still question the proportionality of Israel's response on the ground that proportionality encompasses some consideration of efficacy. If the bombings and imminent ground invasion are likely to fall very short of the goal of "destroying" Hamas, then the civilian toll would be disproportionate.
To be clear, these considerations must be assessed ex ante. Moreover, as I emphasized in an essay on this topic in 2009, the proportionality prong of the international humanitarian law of war evaluates proportionality relative to immediate tactical objectives, not relative to larger strategic goals. But surely those strategic goals should matter to morality and, well, strategy. Here's how I put that point in 2009:
If we think about these issues from the standpoint of morality, rather than international law per se, we might think that whether civilian casualties are proportionate depends ultimately on the value of the military objective. I have real doubts about the likely impact of the current operations by Israel. It seems to me that they will further radicalize Palestinians---not just in Gaza but also on the West Bank---and thus render less likely any lasting peace either with Fatah or with the less ideologically fanatical members of Hamas. And if the whole operation will, in the long run, decrease rather than enhance Israel's security, then it is hard to see how any civilian casualties are [morally] proportionate to the operation.