The Abu Ghraib Prisoner’s Dilemma, Revisited

If you will look to your right, you’ll see that I’ve added The Rumsfeld Wire, an application created by the DCCC that tracks blog posts relating to Abu Ghraib and/or removing Rumsfeld. Now, I think the Abu Ghraib scandal is a true scandal, and deserving of all the abhorrence it has received and probably more, the tragic events surrounding Nick Berg notwithstanding. However, I’m actually not ready to embrace Rumsfeld’s removal.

Even as I type that, I’m surprised. Rumsfeld’s done little right that I can think of, and if he’s been superb then I’m due for the next Nobel Prize in Economics. My primary concerns with Rumsfeld leaving his position in the next six months are the prospect of (1) the gigantic clown circus his successor’s confirmation hearings would inevitably create, and (2) Paul Wolfowitz running the show in the interim. So I’m not personally advocating his ouster at this point, but I will certainly not argue with those who do, nor side with Rumsfeld’s defenders. The best plan, of course, remains getting rid of the entire lot of them.

By way of contributing to The Rumsfeld Wire, I’m reprinting a post from 5/2 that I think has, sadly, proved true. (The post was no great act of prophecy; the escalation was all too predictable. But it does point to a way out — as Lindsey Graham said, “When you are the good guys, you’ve got to act like the good guys.”)


The Abu Ghraib Prisoner’s Dilemma

Phil Carter’s Intel Dump is the place to go for real-time analysis of military issues, from a former Army officer. Reading Phil’s thoughts on the Abu Ghraib situation, I was struck by this passage:

What’s worse is that other American soldiers may suffer for the brutal excesses of these MPs, interrogators, and OGA (“other government agency” = CIA) employees. Reciprocity is a very real thing where the laws of wars are concerned, and we should be very concerned about retaliation against any Americans captured by Iraqi insurgents in the future. Similarly, reprisals are very real problem in war; they’re often fueled by anger over mistreatment of one side’s own troops.

Carter is describing a classic Prisoner’s Dilemma: a situation in which, when two opposing parties pursue actions in their own best interest, the outcome for each is worse than if they had instead cooperated. Such instances are called prisoner’s dilemmas because the canonical example is two prisoners being interrogated in separate rooms. Each suspects the other will confess and so confesses in order to receive a lighter sentence, even though they would both be better off had neither confessed. Attempting to maximize short-run gain results in each party being worse off than if they had followed a cooperative strategy.

If, however, the game is repeated indefinitely, the outcome can change. In repeated interactions, one player can reward cooperation by the other player by cooperating tomorrow. A common outcome involves tit-for-tat strategies: each side pursues the cooperative action; if, however, one side should fail to live up to its side of the deal by taking an opportunistic action, then the other side will respond by also taking the opportunistic action in the next period.

One of the more classic examples of a repeated Prisoner’s Dilemma is in John Axelrod’s book, The Evolution of Cooperation. There, Axelrod (*) examines accounts of trench warfare in World War I, noting how on a day to day basis, the opposing troops pursued a cooperative strategy that basically entailed not shooting every enemy soldier they could:

A fascinating case of the development of cooperation based on continuing interaction occurred in the trench warfare of World War I. In the midst of this very brutal war there developed between the men facing each other what came to be called the “live and let live system.” The troops would attack each other when ordered to do so, but between large battles each side would deliberately avoid doing much harm to the other side — provided tthat thte other side reciprocated (p. 61).

… the historical situation in the quiet sectors along the Western Front was an iterated Prisoner’s Dilemma. In a given locality, the two players can be taken to be the small units facing each other. At any time, the choices are to shoot to kill or deliberately to shoot to avoid causing damage. For both sides, weakening the enemy is an important value because it will promote survival if a major battle is ordered in the sector. Therefore, in the short run it is better to do damage now whether the enemy is shooting back or not … mutual defection is preferred to unilateral restraint [and] unilateral restraint by the other side is even better than mutual cooperation. In addition, the reward for mutual restraint is preferred by the local units to the outcome of mutual punishment, since mutual punishment would imply that both units would suffer for little or no relative gain (p. 75).

Thus, there is a long history supporting Carter’s claim that “reciprocity is a very real thing where the laws of wars are concerned” and we should, therefore, be very concerned about reprisals against captured Americans. Each side can realize some gain by torturing its captives (e.g., intelligence and propaganda); the cost of doing so is that their respective troops are more likely to be tortured in the future. When either side does so, it gains some strategic advantage (we assume — otherwise they would not use torture), but over the long run, there is little relative strategic advantage when both sides employ extreme measures.

For example, just today [5/2/2004], we received the good news that Halliburton truck driver Tommy Hamill escaped after three weeks in captivity near Baghdad. Part of the reason Hamill was able to escape is that he had not been beaten, tortured, and chained. The likelihood of such restraint in the future is now, sadly, less than it was before Iraqis learned of the abuse at Abu Ghraib.

A paradoxical aspect of this situation is that to avoid the outcome in which both sides use torture, it must be the case that both sides are in fact willing to resort to torture or other vicious measures. Otherwise, the threat to punish the other side tomorrow for resorting to torture today is empty. Returning to the trench analogy, if the Germans never retaliated then the Americans would have no incentive not to shoot. It was the proven willingness of the Germans to strike back that rendered such striking back unnecessary, and vice-versa.

A second implication is that, in order to sustain the “cooperative” outcome in which torture is not used by either side, each side must also be willing to not use torture even when there are short-run benefits to doing so. Both sides have demonstrated their willingness and ability to break the cooperative, reciprocal, tacit agreement (see Fallujah and Abu Ghraib, respectively.) An open issue is whether the situation will spiral into a descending series of reprisals and counter-reprisals or whether reciprocity will emerge.


(*) See Chapter 5, The Live and Let Live System in Trench Warfare in World War I.