Foreign policy is considered as the outermost part of the state, which, in addition to introducing macro policies to other actors, pursues all national goals and interests at the international level.In general, an extensive set of internal and external factors shapes the principles of foreign policy. The physical and internal structure of the state and society form an important part of the internal factors, and the international system, its structure and its evolution are among the environmental factors. This paper examines environmental factors and how they affect foreign policy. The main question is: "What effect do the international system developments have on foreign policy patterns of states?" Studies show that states display three distinct behaviors in proportion with internal developments of the international system, from the beginning to decline which include: Self-extension, Self-preservation and Self-abnegation." The main purpose of this paper is to study these behaviors according to the various stages of the international system.