Why are we so afraid?

In one day just about 10 years ago, 19 guys managed to kill a number of Americans comparable the number of Americans killed by heart attack, stroke and cancer on that very same day. Since then, we have, collectively, freaked out over our very survival, convinced that an American caliphate is imminent if we don't ban Sharia Law immediately. Despite spending huge sums and thousands of lives in pursuit of security, we are just as afraid as ever. We have tremendous advantages when it comes to national defense. With two huge oceans between us and most of the world, it is exceedingly unlikely that we would ever be invaded. If it really came down to it, we could at least defend the borders no matter what. And yet we overreact to every threat as if it's an existential peril. The next few posts will look at ways to achieve true security and the benefits that would come from that security.