Our biggest weakness is that people in the western democracies don't fully understand the destructive power of nuclear weapons, and so they don't understand that we cannot absorb a nuclear first strike--not even once. I think Iran understands this fact. Some Iranian officials have said publicly that Iran has a plan to destroy Anglo-Saxon civilization (meaning the United States and Great Britain). If they actually do have such a plan, I'm sure it calls for a massive nuclear first strike. That's why we must stop Iran from building those first few nuclear weapons, which they could use as a defensive shield for a major nuclear program to build a huge nuclear arsenal.
Is there such a thing as an anti-nuclear device?
Well, our economy certainly can't withstand even a relatively small nuclear detonation on our home soil. We have an amazing economy, truly robut...but it's also a fickle economy (sort of like a Porsche - fast, powerful, but fickle and prone to mechanical trouble).
Different issue, but that's why Bush is so unnervingly careful about everything from truly going whole-hog after Islamofascism (oil vulnerability) to the southern border with Mexico (our economy's insatiable thirst for more and cheaper labor). It's because he knows the first way to a collapsed presidency is through a crippled, or even damaged, American economy. Our voters will not tolerate it for any significant time. No presidency could survive it politically. So everything he does, every compromise he makes, is to keep the economy humming. It's where America lives -- it's the true third rail of politics.