When you're in a car and you see you're about to hit something, it's important not to overcompensate and swerve too far in the other direction, else you might run into something else. It's hard to think about this rationally, though, when overcome by the fear of an impending car accident. Fear is a useful motivator in emergency situations, but the rest of the time it tends to cause problems. We can see recent evidence of this in Iraq and America. When we spend so much energy worrying about what might happen, we can easily lose sight of what is happening.