Terrorism is a coercive strategy used by groups seeking to compel stronger enemies to accept their demands. To better understand the logic of terrorism and its inherent limitations, we should look beyond terrorists’ offensive capabilities and examine how terrorist groups undermine their enemies’ legitimacy. State legitimacy depends in part on a state’s ability to provide security to its population, while adhering to a set of rules and norms regarding domestic and international behavior. Terrorist groups aim to show that states are unable to provide security to their citizens, pushing governments to take extraordinary security measures that erode the rule of law and the social contract between a state and its society.
Although terrorists can disrupt a state, attaining their strategic goals, such as independence or regime change, is much harder. This is in part because the politics of legitimacy is a double-edged sword: success often requires adopting norms to gain international acceptance—the very same norms that terrorists flout as part of their campaigns of terror.
Terrorist groups exploit states’ traditional defense paradigms using asymmetrical tactics. In their quest for security, states are accustomed to assuming that rival states are the only threat to their survival. But, when every crowded street and shopping mall is a potential target, traditional defense becomes obsolete. States are often left to choose between unappealing options when confronting terrorism, appearing incompetent in the face of a small force or pursuing solutions that violate rules for legitimate use of state power.
The challenge is greatest for Western states. Citizens’ expectations determine terrorists’ ability to erode public trust in the competence of a government. Western populations expect their governments to provide a high level of personal security, while adhering to international laws and norms. However, such expectations are incompatible in light of an individuals’ or groups’ ability to inflict widespread harm by employing simple measures and weapons—such as motor vehicles. The result? A greater pressure on Western states to provide an unrealistic level of security, which in turn leads to disproportionate responses. The 2013 Boston Marathon bombing, and subsequent lockdown, demonstrates how a state response increases the impact of even a small-scale terrorist attack.