According to Tomja, system polarity refers to the number of blocs of states that exert power in the international system. There are three types of polarity, namely multipolarity, bipolarity, and hegemony. Multipolarity is where there are several influential actors in the international system which balances power. Bipolarity is where there are two influential actors which balance power in the international system. Bipolarity was witnessed during the cold war when the USSR and the U.S. had a strong influence in the world system. Hegemony is a system where only one state influences the international system. The bipolar structure was formed after World War II. The bipolar structure during the Cold War was functioned from various dimensions such as the military potential, and the type of political regime (Tomja 58). As from the 1950s onwards, only the U.S. and USSR were at the same level to be determined as polar actors, but after the Cold War especially in the 1990s, the USSR lost its status making the U.S. emerge as the single largest economic, political, and military power of the world (Tomja 59). Under the unipolarity structure, the superpower always tend to solve relevant, and important international, without engaging other states in doing so.
In a multi or bi-polar structure of the world system, it becomes difficult to control a particular incident across borders due to different political, economic, and military view. However, in unipolarity structure, it is easy to control the world because there is no conflict of interest in any form of intervention by the unipolar state. A good example is the case of the U.S. intervention in the War in Afghanistan. The U.S. being the superpower has total control of the world system. As a result, it had control over the War in Afghanistan, which led to the restoration of world order, especially after the death of the Al-Qaeda leader, Osama Bin Laden. The same hegemony of the U.S. led to the end of Sadam Hussein in Iraq. The unipolarity of the U.S. enabled it to execute military operations in Iraq and Afghanistan without necessarily consulting or sharing ideas with another power because, during the Afghanistan war, the U.S. had already assumed the unipolarity status.
According to the Essentials of International Relations, international organizations tend to regulate the roles of the bipolar systems. Moreover, various hegemonic stability theories state that unipolarity usually establishes a more stable system. For instance, as described by Essentials of International Relations, Paul Kennedy, a hegemonic theorist argues that the hegemony of Britain in the 19th century and that of the U.S. during the Second World War led to the greatest stability. The same would apply to the case of Afghanistan and Iraq, where the hegemony of the U.S. is seen to have brought stability in the two countries. Suppose the bipolar system continued to exist to date, it would have been difficult to achieve stability in these two countries because the other party especially the USSR would have sympathized with the chief culprits in these wars and this would have further jeopardized the stability both in Iraq and Afghanistan. According to Ikenberry, unipolarity is important in maintaining world order, and the loss or decline of power by the hegemon can jeopardize the stability of the international system.
Essentials of International Relations, Chapter 4: The International System |, 5E: W. W. Norton Studyspace”. Wwnorton.Com, 2019, http://www.wwnorton.com/college/polisci/essentials-of-international-relations5/ch/04/summary.aspx.
Ikenberry, G. John, Michael Mastanduno, and William C. Wohlforth, eds. International relations theory and the consequences of unipolarity. Cambridge University Press, 2011.
Tomja, Alida. “Polarity and International System Consequences.” Interdisciplinary Journal of Research and Development 1.1 (2014): 57-61.