At root, much of the debate hinges on different strategic judgments about the relative costs of (a) allowing Iran to develop a nuclear bomb versus (b) using force to prevent such an outcome. In other words, the debate revolves around whether the benefits of anticipatory military action outweigh its costs.
Political scientists have distinguished between two types of anticipatory action which are often confused: preemption and preventive war. Preemption refers to action taken in anticipation of an imminent, certain threat to your country’s interests. A good example is the 1967 Six Day War, in which Israel saw Egypt and Syria preparing to attack and struck first, achieving a dramatic victory. Preemption is commonly viewed as equivalent to self-defense and is typically seen as legitimate under international law and Just War Theory: if you are about to be attacked, you are under no obligation to sit there and “take the first punch,” when striking first can reduce your losses.
In contrast to preemption, preventive war occurs when action is taken in anticipation not of any certain imminent threat, but of some likely future threat. Historically, declining hegemonic states have contemplated preventive war against rising challengers so that the war would happen on their terms, while they still had military superiority. Because preventive war targets some future, uncertain threat it is much more controversial, ethically and legally, than preemptive strikes. The post-9/11 “Bush Doctrine,” as articulated in the 2002 National Security Strategy of the United States and manifested in the 2003 Iraq War, actually focused on preventive war although it was commonly referred to as “preemption.” Given the absence of any imminent nuclear threat from Iran (as all sides acknowledge), the current debate over striking Iran centers on preventive war as well.
What do you think? What would be the consequences of allowing Iran to acquire nuclear weapons? What would be the repercussions of a preventive strike against Iran? Do the costs of preventive war outweigh the benefits in this case? And can a first strike against a country that has not attacked the U.S. directly be justified in moral and legal terms?