The expected utility of drone strikes


A recent article in The Economist asks whether US drone strikes in Pakistan help or hinder the war on terror. A friend of mine explained to me why he thought they did more harm than good. Suppose a drone strike takes out two Al Qaeda operatives, he said, but causes several civilian casualties too. The outrage caused by this collateral damage will inflame anti-US sentiment in Pakistan, and some of that sentiment will translate into support for Al Qaeda.  Some of that support will further translate into some people actually joining Al Qaeda.  Even if only 0.1% of Pakistanis are sufficiently outraged by the drone strike to support Al Qaeda, and only 0.1% of them will actually join the organization, that is still 170 new recruits (since Pakistan has a population of 170 million).  So the net gain for Al Qaeda is 168 terrorists (170 new recruits minus 2 casualties).

Of course, the precise figures will depend in part on the ratio of terrorists killed to civilian casualties, and there is some disagreement about this.  In his excellent book, Task Force Black, the BBC journalist Mark Urban claims that “most of the people killed in these attacks are innocent bystanders” (p.xiv, Foreword to Paperback Edition,2011). But The New America Foundation, a Washington think-tank, estimates that 80% of the 2,551 people killed in drone strikes since 2004 were militants, rising to an astonishing 95% in 2010. The expected utility of drone strikes could depend crucially on who is right.

Even if the drone strikes mainly kill militants, their utility may also depend on whether these are terrorist chiefs or low-level fighters. According to the New America Foundation, out of the 2,551 deaths, only 35 were recognized militant chiefs, or just 1.3% of the total. Among these high-level hits was the fearsome leader of the Pakistani Taliban, Baitullah Mehsud, who was the country’s number one public enemy. Nevertheless, the vast majority of targets have been low-level fighters.

There are also disagreements about local perceptions.  While those in Islamabad might react with anger, many locals privately support the strikes against extremists who have overrun their homeland.  What may inflame anti-US sentiment more than the civilian casualties in themselves, however, may be the lack of transparency and accountability. There is no investigation of civilian casualties, and no compensation paid, and some question the legal basis of the attacks.

It is probably too early to be sure whether the drone strikes are harming al-Qaeda and related groups, or spurring on Afghanistan’s powerful insurgency.  But my friend’s argument does at least set out the terms in which we should be thinking about this question, and suggest the kinds of data we need to collect before we can reach a definitive verdict.  How, for example, can we measure anti-US sentiment? And what objective metrics might we use to judge overall success?  One such metric might be the number of suicide attacks in Afghanistan.  Unfortunately, on this measure, the drone strikes do not appear to be achieving their aim; over the past year, the number of suicide attacks in Afghanistan, many launched from Pakistan, has soared.

The rational terrorist

In my previous post, I put forward a utilitarian argument against suicide bombing.  The idea was to accept, for the sake of argument, the premises from which jihadis start - to argue, in other words, entirely within their framework – and show that suicide bombing is still wrong even when one accepts all the theological tenets of fundamentalist Islam.

I didn’t quite succeed.  For one thing, utilitarianism is itself not one of those tenets; there are important deontological elements in the moral universe of the Islamist, as is clear from the following conversation with a real jihadi reported by Scott Atran in his fascinating book, Talking with the Enemy:

Atran: What if a rich relative were to give a lot of money to the cause in return for you canceling or just postponing a martyrdom action?

Jihadi: Is that a joke? I would throw the money in his face.

Atran: Why?

Jihadi: Because only in fighting and dying for a cause is there nobility in life.

Atran argues that when people consider things sacred, standard economic models of decision making fall apart, as costs and benefits are ignored in favor of intrinsic values. Does this mean that Islamic terrorism is always irrational?  Or does the attempt to apply expected utility theory to suicide bombing still have something to offer?

Heather Rosoff and Richard John suggest that it may.  They have written a thought-provoking paper entitled “Decision analysis by proxy for the rational terrorist.” Using a decision theoretic framework, they compare the risk profiles of alternative attack strategies and estimate the relative likelihood of a terrorist leader selecting a particular attack strategy.  The result is an interesting perspective on how the values and beliefs of terrorist leaders can shape the decision to select a target.

It is significant that Rosoff and John apply their analysis to the decision making of terrorist leaders – that is, those in charge of planning attacks rather than those tasked with carrying them out. One might expect the leaders to think in more rational ways, weighing up costs and benefits and estimating probabilities, while the poor idiots they send to their deaths are encouraged to carry on thinking in “irrational” ways such as in the conversation reported by Scott Atran I cited above.

The expected utility of suicide bombing

Suicide bombing only makes sense if it helps to achieve some goal.  Even the most rabid Islamist understands that suicide by itself is wrong; only when others are killed does the bomber become a martyr, and reap the supposedly heavenly rewards.  These rewards are presumably dished out because the successful bomber has moved the world slightly closer to wherever Allah wants it to be.

Suicide bomber

It follows that the Caliphate, or at least the moment when it arrives, is not a dead cert.  If it were, there would be no point in suicide bombing, since it would not help increase the odds of the Caliphate coming to be, nor even accelerate its arrival.  Under conditions of such uncertainty, the rational suicide bomber must turn to expected utility theory to calculate the value of his act.

This means he must consider both the costs and benefits of suicide bombing.  The costs include the cutting short of innocent lives and the suffering of those who survive.  But perhaps for the suicide bomber these count for nothing, since he may not view them as innocent bystanders, but as wicked heathens.  Their elimination would then be, not a cost, but a benefit.  The other benefits are both personal and global, but the value of moving the world closer towards its divinely appointed goal must far outweigh the heavenly rewards for the individual martyr.  Indeed, the value of the global goal must be infinitely greater.

Besides the costs and benefits, the rational suicide bomber must also consider the probability that his act will incur these costs and produce these benefits.  The probability that others will be killed is high.  The bomber is likewise confident that he will go to paradise.  But what are the chances that his act will make the Caliphate more likely, or hasten its arrival?

It is at this point in his calculations that the rational suicide bomber must consider empirical data. What does the evidence tell us?  Does suicide bombing help or hinder the advance of radical Islam?  Have terrorist acts in the past made the Caliphate more or less likely?  For if it turns out that suicide bombing makes it even slightly less likely, there is simply no justification for it even in the mind of the most fanatical Islamist.  The expected utility of an action which reduces the likelihood of an infinitely valuable state of affairs, or retards its arrival, is infinitely negative.  None of the finite gains could possibly be worth such infinite costs.

It follows that Islamists should assiduously research the question of whether suicide bombing helps or hinders their cause.  Unfortunately for them, the answer does not point in the direction they might like.  Despite the thousands of martyrdom operations in the past decade, the Caliphate looks no more likely than it did before 9/11.  Indeed, it now seems even less likely.  Many Muslims have been shocked and disgusted by the tactics of al Qaeda.  The popularity of this organization in its homeland, Saudi Arabia, was severely dented in 2003, for example, when most of the victims of the attack on the al-Muhayya housing compound in Riyadh turned out to be Saudis and other Muslims.  By any rational consideration of the evidence, then, suicide bombing would seem to move the world further away from a new Caliphate, not closer towards it.  Martyrdom operations cannot therefore be justified, even when one accepts all the theological tenets of fundamentalist Islam.

The benefits of al Qaeda in Iraq

In my last post, I noted the general failure in the US to foresee the insurgency that began to emerge in Iraq in the summer of 2003.  In his autobiography, Donald Rumsfeld admits that he didn’t see a single “briefing that anticipated the likelihood of a sustained guerrilla campaign against the coalition” (p.520). But there are two ways of framing this admission. One is to say that nobody foresaw the risks of a full-scale insurgency in Iraq;  another is to say that nobody foresaw the benefits.

Risk analysis is incomplete unless one considers both the costs and benefits of each risk. That applies as much to the insurgency in Iraq as to anything else;  even this cloud has a silver lining.  During the US bombardment of Afghanistan in October-November 2001, many al Qaeda members fled their bases there to return to their native Saudi Arabia (around 70 per cent of al Qaeda’s membership is Saudi, as were 15 out of the 19 hijackers in the 9/11 attacks).  Not long after, al Qaeda began to establish cells in Saudi Arabia, which became the backbone of its new franchies, al Qaeda in the Arabian Peninsula (AQAP).  AQAP carried out its first attack on 12 May 2003: a mass suicide bombing by nine operatives who blew up three housing compounds for foreign workers in Riyadh, killing 35 and wounding 200.

Not long after, the first signs of what would become the insurgency in Iraq began to appear, with a string of attacks against US forces in Baghdad and Falluja.  Muslim resentment of the occupation forces grew when photos of physical, psychological, and sexual abuse of prisoners held in the Abu Ghraib prison came to public attention in April 2004.  In October that year, Abu Musab al-Zarqawi announced that he was changing the name of his al-Tawhid wal-Jihad group to al Qaeda in the Land of the Two Rivers, thus establishing a new al Qaeda franchise specifically focused on Iraq.  The following month, twenty-six Saudi Islamic scholars signed an open letter calling on Muslims to fight the US in Iraq and consider it jihad.  According to Sa’ad Al-Faqih, official Saudi figures showed 3,000 nationals left for Iraq in the following two years.

Muhammad al-Masari claims that “the Saudi regime is happy that these jihadis are going to Iraq and are not staying to carry out operations inside the country” (cited in The Secret History of Al Qaeda, p.172). Despite US complaints about lax Saudi border security, there is reason for the US to be happy with this movement too.  Since 2002 al Qaeda’s leaders have placed increasing importance on pushing up oil prices with the intention of squeezing Western economies, and in December 2004 AQAP issued a statement urging jihadis in Saudi Arabia to focus on oil targets. There is unlikely to be a great deal of al Qaeda activity in the kingdom, however, until the insurgency in Iraq is over, because thousands of Saudi jihadis are engaged in battle there.  It may well be in America’s interests, then, not to drive the insurgents out of Iraq;  by keeping the jihadis locked down there, they may be preventing a much greater disaster elsewhere.