Suppose your friend is strong on defense and insists we must bolster our national defense, whatever the cost. how can you use economic logic to make him or her aware of the opportunity costs with his or her objective?

Opportunity cost is the benefit cost that a person could have had is lost when one is chosen between an alternative given. So if you choose to the side of defense and bolstering it whatever the costs, we may have so many lost opportunity costs at our hands. The allocated material for the construction, the costs for these materials are very expensive if a country has to improve its defense. The people that will serve for the defense, not only in the military section but the country must hire and train other men or women to help in the defense. The property that has to be destroyed to replace it with a fence or wire for defense.