Realism: not quite as good as it could be...
             Realism is a powerful theory that tries to but ultimately cannot be successfully applied to foreign policy. Realism place too much focus on power alone. This by itself is the fatal flaw of the theory. Realism does not take into account such things as non state actors, ideas instead of focusing explicitly on power, and units below the state, which is regarded as the smallest unit in realism. These short comings illuminate the superiority on constructivism in these aspects. Both theories are strong in there own right, but if combined and made so that their strengths compliment each other could be the best ideology to make foreign policy from. By adding some constructivist aspects to realism one can differentiate between a nation's power relative to itself from a nation's relative threat.
             It is the leaders that implement foreign policy and their beliefs will affect the way they want their nations to interact with others. Because leaders can choose their own actions it is good to be able to take into account the leaders perception and ideologies. With realism one would not be able to accomplish this by just looking at the state. The state has no feelings and no perception. One leader's ideas can change the course that the nations takes. One obvious example is Gorbachev. These types of ideological changes stem from change perception on the part of the leader. If a leader feels that another state is a threat then the state perceives it as a threat due to the projection of these traits to the state. Power will always be a major determinate in allocating threat but the idea that goes along with the power determine the perceived threat. This allows for nations that are allies to appear lower on the "threat list" than nations that do not have nearly as much power. These nations' ideas coupled with their potential power can become the largest threat ...