A. The Cold War (1949-1991) was an era of greater danger for the national security of the United States than is the era that began in 1991 and continues today, even after 9/11. The threat of nuclear destruction, a global competition for allies and economic resources, and four decades of espionage and counter-espionage as well as other matters comprised a system of world politics that presented greater danger to Americans than the current world system.
or
B. The Post-Cold War era (1991-present) presents greater danger to the national security of the United States than did the era of the Cold War. The Cold War nuclear threat was obviously a high-level threat, but by the 1960s (after the Cuban missile crisis) the United States and the Soviet Union constructed a relationship which remained hostile but realistic and in which the purposeful use of nuclear weapons was highly unlikely. In contrast, the United States faces a world of many dangers, from hostile and growing competitors like China and Iran to very flexible and violent terrorist and criminal organizations that do not align with the world's national borders. The threat of a terrorist organization obtaining and using a nuclear weapons is more likely than was the launch of a thousand nuclear weapons by the Soviet Union.
Explain your answer and be sure to address both sides, discussing why support one and oppose the other. Be specific and cite any sources you use.