The Fallacy of Proportional Response

Somehow we in the U.S. have adopted the idea that it is unfair to respond to terrorist acts, or other acts that harm our country or citizens, in other than a proportional way. Perhaps this comes from the Biblical “eye for an eye” or maybe our justifiable belief that revenge is wrong. Consider the issue of revenge first.

The word “revenge” has a negative connotation despite the fact that surveys show that over 50% of people in the U.S. support the philosophical concept. The arguments against generally fall into the areas of: take the moral high ground, violence precipitates violence, and two wrongs do not make a right. The arguments that revenge is justified tend to revolve around protection against future actions (deterrence) and that the punishment should fit the crime, i.e. proportional response. All of these arguments are made in other cultures, but the fraction of revenge supporters varies greatly by culture, with some cultures believing it to be a moral imperative. This essay does not really address the rightness or wrongness of revenge, but rather the idea of proportional response.

If one makes the argument that a punitive response should be made when people or society are wronged, in most cases the reason for this is to prevent future such actions by the same or other perpetrators. This is why we have prisons, military, police, etc. The idea of proportionality is that the punishment fits the crime. This is usually interpreted as equal hurt for both parties. For example, you kill and you are killed (executed), or you speed and you are fined, or …

Now consider a rational actor (rational by their own definition rather than yours or mine) as he considers some future action. He weighs both the value of his action and the consequences if caught. In an environment where proportional response is the consequence, the value and the consequence are roughly equal(by definition.) So there is neither a deterrence nor an incentive for the action. But wait, did we forget the “if caught” clause? Don’t most evil-doers believe they are of the criminal genius elite and are highly unlikely to be caught? If this is the case, there is no deterrence associated with a proportional response because the worst that could happen is that the perpetrator makes an even trade, and that is unlikely in his mind so his expected gain is positive. The idea of proportionality is flawed in this respect.

How does this relate to terrorists willing to lay down their lives for their cause? Willingness to die makes the idea of punishment as a deterrence moot. We in the US tend to think of execution as the ultimate punishment; but for today’s terrorist our ultimate punishment may be considered a reward and hence has no deterrent value whatsoever. Deterrence only comes when it causes the perpetrator to risk something he/she is unwilling to give up. Two possibilities come to mind when considering radical Islam, serious adverse impact to their cause and their families. In either case achieving deterrence requires a non-proportional response, most likely killing hundreds or thousands for a terror attack that kills tens of people. A highly non-proportional response.

Until we eliminate the idea of proportional response we will be fighting a losing cause while any terrorists remain alive.