SUMMARY-This monograph examines from a psychological perspective the use of metaphors in framing counterterrorism. Four major counterterrorism metaphors are considered, namely those of war, law enforcement, containment of a social epidemic, and a process of prejudice reduction.The war metaphor is as follows: Wars are fought by states; the enemy is thus an identifiable entity whose interests fundamentally oppose your own. The conflict is zero-sum-the outcome will be victory for one side or the other-and there is no compromise. The war metaphor is totalistic and extreme. Arguably, it was adopted in light of the immensity of damage and national hurt produced by the 9/11 attack. It has insinuated itself into the public discourse about counterterrorism, and it has guided policy, but it has also met challenges because of lack of fit and the availability of counteranalogies with different lessons of history.Some of the drawbacks of the war metaphor are addressable in the law enforcement metaphor of counterterrorism. Unlike war's special status and circumscribed duration, law enforcement is an ongoing concern that must compete for resources with other societal needs. A major advantage of law enforcement over warfare is its focused nature-targeting the actual terrorists, with less likelihood of injuring innocent parties. Yet despite its advantages, the law enforcement metaphor exhibits a partial mismatch with the realities of terrorism. Its complete and uncritical adoption may temporarily hamper terrorists' ability to launch attacks without substantially altering their motivation to do so.The public health epidemiological model was usefully applied to the epidemic of terror that followed the 9/11 attacks. It utilizes a partition between (a) an external agent, (b) a susceptible host, (c) an environment that brings them together, and (d) the vector that enables transmission of the disease. In the specific application to jihadist terrorism, the agent refers to the militant Islamist ideology, the susceptible host refers to radicalizable Muslim populations, the environment refers to conditions that promote the readiness to embrace such ideology, and the vectors are conduits whereby the ideology is propagated. The epidemiological metaphor has its own advantages over the war and law enforcement metaphors, but also limitations. Whereas the latter metaphors neglect the long-range process of ideological conversion and radicalization that creates terrorists, the epidemiological metaphor neglects the ''here and now'' of counterterrorism and the value of resolute strikes and intelligence-gathering activities needed to counter terrorists' concrete schemes and capabilities.Framing counterterrorism as the process of prejudice reduction addresses the interaction between two communities whose conflict may breed terrorism. This framing shifts the focus from a unilateral to a bilateral concern and acknowledges the contribution to intergroup tensions that the party targeted by terrorists may make. A major tool of prejudice reduction is the c...