undermine the stability of the international system? Does the Rus sian intervention,
coupled with Rus sian activities in Crimea and the Ukraine, indicate a change in the
balance of power in the international system? Will a resurgent Rus sia alter the struc-
ture of the international system?
Each of the contending theoretical perspectives examined in Chapter 3 describes
an international system. For realists and radicals, the concept of an international
system is vital to their analyses, whereas for liberals— who focus much more of their
analyses on key characteristics of states— the international system is less consequen-
tial. For constructivists, the concept of an international system is tied to notions of
identity as derived from norms, ideas, and discourse.
To understand the international system, we must first clarify the notion of a sys-
tem itself. Broadly defined, a system is an assemblage of units, objects, or parts united
by some form of regular interaction. The concept of systems is essential to the phys-
ical and biological sciences; systems are composed of dif er ent interacting units,
whether at the micro (cell, plant, animal) or the macro (natu ral ecosystem or global
climate) level. Because these units interact, a change in one unit causes changes in
the others. With their interacting parts, systems tend to respond in regularized ways;
their actions have patterns. Bound aries separate one system from another, but
exchanges can occur across these bound aries. A system can break down when
changes within it become so significant that, in efect, a new system emerges. In this
chapter, we look at how po liti cal science defines and views the international system,
and how we can use the international system as a lens through which to analyze inter-
national po liti cal events.Learning Objectives■ Explain why the concept of a system is a power ful descriptive and
explanatory device.
■ Understand the concepts that realists, liberals, radicals, and
constructivists employ to analyze the international system.
■ Describe how each of the contending theoretical perspectives explains
change in the international system.
■ Analyze the prob lems and/or weaknesses with the notion of the
international system.108 CHAPTER FoUR ■ t he internatiOnaL systemESSIR7_CH04_106_131_11P.indd 108 6/14/16 10:04 AM