There are perhaps four “explanatory models” or theories for understanding international politics and international relations. For one, there is “Realism,” where the basic assumption is that the international system is in a state of anarchy and chaos, and thus power is the basic currency of states who are the basic units of the international system, who in turn aim for their basic survival. Second, there is “Liberalism,” where the reality of economic cooperation and economic interdependence means that international order and the international system must be governed by a set of commonly agreed upon rules and norms. Third, there is “Constructivism,” where the basic notion is that international order is socially constructed through diplomacy and social interaction. Finally, there is “Personality Theory,” whereby personalities and individuals are seen as the main actors or forces in shaping the realities of the international system. Each explanatory model or theory carries its own level of weight. One cannot say that one explanatory model or theory is correct and that the others are wrong.
Also, there are limits to the applicability of both realism and liberalism. At times, anarchy and chaos cannot serve as a legitimate pretext for certain actions and policies. In turn, liberalism cannot override political will, nor does it cancel the degree to which realpolitik exists between nations and states. There is also the issue of structure and stability in the international system which realism addresses to a certain extent. It must be noted that unipolar systems, such as the one we witnessed at the end of the 20th century and 21st century, are actually unstable because of the hegemonic actions and policies of the unipolar power. Thus, it has been argued by certain realist scholars that the most stable international structure and system is a bipolar system, given that there is balance and power equilibrium in the international system as a result of bipolarity.
Thus, when the dust settles after the demise of the ‘American Unipolar Moment’ and as China rises, uncertainly and volatility may in fact be a segue for the structure and stability which ensues from a bipolar system, whereby the United States and China serve as the two basic poles of a bipolar international structure and system. China is still very much rising as a military and economic power, whereas the United States is reeling from decades of corruption and war and is thus in a state of “relative decline” vis-à-vis China. But America’s “relative decline” vis-à-vis China is not necessarily an “absolute decline.”
Thus, once the limits of China’s rise have been reached given that power is not absolute, and once the limits of America’s “relative decline” have been reached given that decline is not absolute, the result may in fact be an international structure and system defined by bipolarity and thus order and stability may materialize to a large extent. Although there has been talk of a “multipolar system” arising, there is no clear evidence to suggest that we are headed more towards a multipolar system rather than a bipolar system. I would argue that we are headed more towards a bipolar system rather than a multipolar system. But everyone is entitled to their opinion.