[NSP Report 33] The History of Alliances

Professor Jeon Jae-sung graduated from Seoul National University with a degree in Diplomacy and obtained a Ph.D. in Political Science from Northwestern University in the United States. He then served as an assistant professor in the Department of Political Science and International Relations at Sookmyung Women's University and is currently a professor in the Department of Diplomacy at Seoul National University. His major publications include "The Christian Realist International Political Thought of Reinhold Niebuhr," "An Essay for Realist International Institutional Theory," and "U.S. Policy Toward Korea Regarding the Normalization of Relations between Korea and Japan in 1965 and the Dispatch of Troops to Vietnam."

I. Introduction

The history of human groups forming military alliances to strengthen their military capabilities is long and extensive. However, the form and content of military alliances can vary significantly depending on who possesses military power, who the political actors forming alliances are, the reasons and objectives for forming alliances, and the level of military technology. In modern international politics, which has its origins in the European regional order, military alliances were formed by modern nation-states that monopolized military power. Considering that modern states, the units of modern international politics, possess the nature of war states, economic states, and colonial states, it seems natural that all policies related to the use of military power depend on the decisions of nation-states. However, this situation is unique to modern international politics, where sovereign nation-states are organized anarchically, and alliances before and after the modern era must necessarily differ from the present.

In modern international politics, the most important reason for states to form alliances is the balance of power. In the absence of international institutions that can guarantee a state's security beyond the capabilities of other states, states must pursue security through the principle of self-help and, in the process, seek safety from aggressive or hegemonic states through military alliances with other countries. In the Treaty of Westphalia, which concluded the Thirty Years' War, the territorial sovereigns of nation-states began to acquire autonomy in governing their own states, and in the process, secured the right to conclude alliances. Since then, and up to the 21st century, alliances continue to be concluded, terminated, and function among nation-states.

In the early 21st century, various alliances exist in the world. On a global military scale, the unipolar system led by the United States continues, and there is currently no power that can balance the United States and its allies. In this context, new questions arise regarding alliance theory in the 21st century. Is the logic of power balance and the alliance system based on the sharp confrontation between the two major camps of the U.S. and the Soviet Union, which existed until the Cold War, no longer sustainable? That is, in the current era where the United States has established a unipolar system, does the logic of military power balance not apply, and are the current alliance systems composed of alliances for balancing interests to gain advantages by aligning with U.S. power? If so, do current alliances pursue other political objectives beyond responding to military threats, rather than postulating explicit enemies?

This chapter seeks to partially answer these questions raised about the present by examining the history of alliances under the modern international political system, considering theoretical perspectives. What this chapter aims to show through a historical overview of alliances is, first, that even if the U.S. military unipolar system continues in the early 21st century, the necessity of balancing U.S. hegemony itself has not disappeared, and the possibility of forming alliances derived from policies of balancing against the U.S. cannot be ignored depending on future developments.

Second, regional balances of power still operate under the U.S.'s global military unipolar system, and since the U.S. cannot function as a military balancer in all regional conflicts, alliance systems to respond to regional threats are still in operation.

Third, with the beginning of the post-Cold War era, political objectives advocated by actors other than nation-states have begun to emerge, and some of these objectives have been combined with military means. As clearly demonstrated by the 9/11 terrorist attacks, non-state military groups such as terrorist organizations continue to operate, and nation-states that perceive these as military threats feel the need to maintain military alliances to counter terrorism.

Fourth, although the current power distribution structure clearly shows a U.S. military unipolar system, power transition phenomena are accelerating due to the economic rise of new great powers such as China. In a situation where countries that have risen economically are expected to grow militarily and form a new power distribution structure, the necessity of maintaining preventive military alliances is increasing. In other words, unpredictability or uncertainty about the future power distribution structure itself becomes the object of balance. Many countries, while conforming to the U.S.-led global order, are partially maintaining their current alliance systems to prevent the emergence of unpredictable and potentially disadvantageous distribution structures.

Fifth, the remarkable development of military technology is accelerating the phenomenon of the rich getting richer and the poor getting poorer in military technology. While the United States spends more than 40% of global military expenditures, it spends more than 80% of the world's costs on military technology research and development, maintaining an overwhelming military technological advantage. In this situation, it is not easy to pursue a military balance of power against the United States, and most countries conform to the U.S.-led order.

Sixth, international politics itself is undergoing many changes due to major trends such as globalization, informatization, and democratization. A notable change is the increasing influence of domestic and international civil society on all policies of nation-states. In the past, government decisions regarding foreign policy in general, and military policy in particular, were not widely known to the public, nor were they subject to criticism. However, in a democratized and informed political environment where governments must make all decisions openly, it is no exaggeration to say that the influence of public opinion has been absolutely strengthened. As public opinion strongly leans towards moralistic and liberal tendencies regarding international politics, the congruence of value orientations between states and the legitimacy of foreign policy have emerged as more important decision-making factors than short-term military interests. Alliances have now reached a situation where they must be formed, maintained, and even terminated considering mutual value alignment, the degree of trust, and elements of legitimacy.

These changes have occurred very slowly throughout history, and in fact, many of the changes in alliances in the post-Cold War era have been abrupt. This chapter aims to provide a clearer view of the ongoing changes in alliances by historically outlining the changes in alliance systems in Europe and the world since the 17th century... (continued)