We're afraid of a lot of stuff these days. We're afraid that our children will act like morons. We're afraid that natural disasters will kill us. We're afraid of being poisoned or harmed by chemicals, injured by our fellow people in both organized ways (like governments) and unorganized (crime).
Our animal ancestors developed fear to urge them towards self preservation. When predators attacked, those that did not escape would die to be eaten. Natural hazards like falling or sharp rocks would also end lives in a rather fast fashion as well. Animals might not comprehend that they will die, but they know scary when they see it.
Unfortunately, as we humans are intelligent, we are also imaginative, and this turns against us. We can conceive of scary situations that have yet to happen, and can plan ahead to avoid negative outcomes. Normally a good thing -- until it runs away on you and you endlessly worry about things that probably won't happen.
Fear is also used politically in the form of terrorism. Scare people enough and you can get them to agree to things just to make it stop. The current military doctrine of the United States is "Shock and Awe," combining the previous Superior Firepower doctrine with mobility to produce armies that rapidly dominate everything around them, terrifying all opposition into running away, or at least quitting the fight. Fear, representing the desire not to die in the face of a dangerous situation, is turned into yet another weapon.
Fear can be pathological. People who are traumatized by situations can develop phobias, in which they are cripplingly afraid of things that imperiled them in the past. A person with a spider-phobia (Arachnophobia) will recoil in horror from even harmless spiders. They will avoid places where they believe even might have spiders, which can easily branch into new phobias. (Arachnophobia leading to a fear of enclosed places, as they may contain spiders.) Psychological help may be required.
Fear has economic consequences too. Depressions worsen as everyone involved attempts to avoid negative consequences, and the economy slows further from lack of spending. A negative cycle develops for quite a while until necessity eventually ends it. In the past, this has generally been a war. Governments must spend bucket-loads of money to win a war, and enough people can receive this spending to begin to buy their favorite goods again, and the depression ends.
Is there a better remedy for fear than psychological counseling?