It’s long been understood that effective deterrence is key to gaining advantage over long-term adversaries. Yet it’s also become all too clear that the lessons of deterrence that can be gleaned form the Cold War are far from adequate to deal with the unique asymmetric threats posed by organized but non-state based terrorism.

A new report released last week by the Rand Corporation addresses the practical implications of this conundrum for homeland security policy making.

The report, titled Understanding the Role of Deterrence in Counterterrorism Security, argues that, although individual acts of terrorism often appear devoid of rational cost-benefit analysis, organized terrorist motivations and tactics can, and must, be understood according to a rational calculus.

“Although determined terrorists, both as individuals and organizations, may be willing to risk everything to achieve their objectives,” the report says, “ they do not wish to waste their own lives or other resources on missions that are doomed to fail or unlikely to achieve their intended results.” Rather, it asserts, “for a terrorist planning an attack, different types of costs and benefits need to be considered.”

The report explains that by thinking about how defensive measures might affect the decisions of terrorist organization, potentially resulting in deterrence or risk displacement, we may be able to anticipate their cost-benefit calculation.

To illustrate this point the report cites a hypothetical example of a simple bombing attack.

“ On the benefit side,” it says, “the bomb will produce immediate damage and casualties that the terrorist hopes will translate into media attention, fear among or coercive power over its target populations or states, and some longer-term progress toward achieving his or her goals.’

Yet even with meticulous planning and preparation, the report adds, “a planner seeking to predict the magnitude of expected benefits for most operations will face considerable uncertainty. Even for something as tangible as the number of people his or her bomb will kill, the actual outcome of an operation can range from nothing (e.g., if the bomb fails or explodes at the wrong time) to the maximum number of casualities a device of its size and characteristics could produce.”

On the cost side, “there are predictable costs”, says the report, “and less-predictable ones (e.g., threats to operational security, dangers associated with handling explosives, and uncertainties in how counterterrorism response after the attack might affect the group. The specific rational calculus of terrorism differs radically, however, from that of more traditional threats.

In criminology literature, the report explains, “ deterrence is thought to be driven primarily by the likelihood and severity of punishment expected for committing a crime . Although both the likelihood and the severity of punishment surely play some role in the decision-making of terrorists, there are important differences between the objectives of terrorist organizations and individual criminals. For instance, most criminal activity has the objective (or hope) of avoiding accountability for the crime.”

The same calculus may not be true for many terrorist acts, however. While the criminal caught after stealing jewels or killing an enemy has failed in what he or she is trying to do, which is to perpetrate the crime and get away with it, the terrorist “may be satisfied with overcoming security countermeasures and executing the attack effectively, and have little regard for his or her fate afterward and only modest concern about the consequences to his or her organization.”

Given the differences between ordinary crime and terrorism, the report suggests “focusing on the potential effects of security measures on terrorist organizations and their objectives rather than on the usual assumptions about how individuals might be deterred from committing crimes.”

Even if terrorist planners are only concerned that the costs of an operation not exceed its utility, the report says, security can be used to manipulate the operational planning of terrorists.

Specifically, it says, security can be designed to increase a terrorist’s views of expected disutilities, lower their estimates of expected utilities and increase uncertainty in expected utilities or disutilities, or exchange the net expected utilities of different operations.

Likewise, the report argues, that while classic deterrence by punishment approaches are essentially designed to affect the perceived cost of an operation therein, or, as in the case of the early Cold War, persuading enemies that US retaliation against any attack would be sufficiently certain and severe to make the cost of attacks appear unacceptably high, such approaches must be modified to deal with terrorist threats.

“ During a period in which the risk of global conflict of sufficient proportions to threaten the survival of the human race was real and immediate,” it says, “ the mutual deterrence that large nuclear arsenals created helped ensure that nuclear warfare between superpowers never happened.”

In contrast, ‘strategic level deterrence-by-punishment may be of limited value against terrorist groups that have little infrastructure of their own to protect against attack, who may well be prepared to lose it all in the service of achieving a significant blow against the United States, and who may be harder to identify and locate after an attack than were the United States’ Cold War adversaries.”

Swift and severe punishment is not the only way to increase the cost of terrorist operations, However, according to the report.

For instance, it says, “ the United States pursues programs to make unconventional-weapon materials more scarce than they might otherwise be, thus increasing the expense and danger to obtain them and thereby driving up material costs.”

As examples the report cites, “ nonproliferation programs employing former weapon scientists were designed to increase the difficulty and cost of purchasing such expertise” and “interventions in other illicit-weapon markets and regulatory controls on explosives have analogous effects for familiar weapons .”

Effective border and immigration controls, it adds, “ could increase the costs of positioning attackers in the United States, if, for instance, they forced operational planners to recruit personnel who would not be identified through terrorist watch lists,” while. other interventions could make it more difficult for attackers to gather the information they require to plan operations, therefore requiring that they spend more time on or involve more people in operational preparation.

Specifically, the report recommends that security increases uncertainty and thus deterrence against terrorism when it:

• presents the attacker with defensive capabilities of unknown or unfamiliar effectiveness or operational characteristics.

• pushes the attacker to adopt more-complex and more-risky tactics, such as those employing unfamiliar technologies or tactics or those with multiple failure modes.

• presents the attacker with random or unpredictable security measures.

However ultimately the report concludes” the potential for risk displacement makes understanding the deterrent effect of a security program a systems problem.”

“ Whether baggage screening produces a strong, broad deterrence against attacks on airplanes,” it says, “ depends critically on the effectiveness of the entire national transportation security architecture. If attackers have few other good options for getting weapons onto planes, the risk that baggage screening will disrupt a planned attack might deter terrorists from attacking air-transportation targets. If alternatives are readily available, however, there may be no deterrence from attacks on aviation.”