An accurate definition of the current IR system and how power is distributed is crucial in forming a sound foreign policy. Roskin and Berry allude to the tendency toward idealism in international politics before WWII ended in 1945, but the tendency toward realism after that year. a. Explain what the authors mean by "idealism" and "realism" in international politics. b. Characterize the differences between the world before 1945 and the world after that year with respect to international relations. c. Explain the causes of the transition (from idealism to realism).

The realism in the international politics refers to the idea that all the countries in the world coexist in an international system with an endless fight for the power. The countries will act in order to reach their interests, preserving their power and satisfying their needs. On the other hand, the ideliasm maintains that all the countries exist in a community which interest in common, everyone defends the same. Their actions must be based on the ideals of humanity.

Previous 1945, Europe did not participate much in the international commerce, it was weak because of the war so the competition of USA and Japan increase in that area. Those countries developed industries and production techniques. After the war finished, many international organisms were founded such as the International Monetary Fund or the United Nations. All the countries, no matter how small they were, have voice there.