It has been common, at least since 1945, to exaggerate and to overreact to foreign threats, something that seems to be continuing with current concerns over international terrorism. This paper sketches threat exaggeration during the Cold War and applies the experience from that era to the current one. Alarmism and overreaction can be harmful, particularly economically. And, in the case of terrorism, it can help create the damaging consequences the terrorists seek but are unable to perpetrate on their own. Moreover, many of the forms alarmism has taken verge on hysteria. The United States is hardly ''vulnerable'' in the sense that it can be toppled by dramatic acts of terrorist destruction, even extreme ones. The country can, however grimly, readily absorb that kind of damage, and it has outlasted considerably more potent threats in the past.