Most international relations theorists locate the origins of the contemporary state system in Europe in 1648, the year the Treaties of Westphalia ended the Thirty Years’ War. These treaties marked the end of rule by religious authority in Europe and the emergence of secular authorities. With secular authority came the principle that has provided the foundation for contemporary international relations: the notion of the territorial integrity of states–legally equal and sovereign participants in an international system. The formulation of sovereignty–a core concept in contemporary international relations–was one of the most important intellectual developments leading to the Westphalian revolution. The treaties that ended the conflict had three key impacts on the practice of international relations. First, the Treaties of Westphalia embraced the notion of sovereignty. Not only did the Treaties legitimize territoriality and the right of states–as the sovereign, territorially contiguous principalities came to be known–to choose their own religion, but the Treaties also established that states had the right to determine their own domestic policies, free from external pressure and with full jurisdiction in their own geographic space. The Treaties thus introduced the principle of noninterference in the affairs of other states. Second, because the leaders of Europe’s most powerful countries had seen the devastation wrought by mercenaries in war, after the Treaties of Westphalia, these countries sought to establish their own permanent national militaries. The growth of such forces led to increasingly centralized control. Third, the Treaties of Westphalia established a core group of states that dominated the world until the beginning of the nineteenth century: Austria, Russia, Prussia, England, France, and the United Provinces (the Netherlands). Those in the west (England, France, and the United Provinces) experienced an economic revival under liberal capitalism. Meanwhile Prussia and Russia in the east reverted to feudal practices.
Two core principles emerged in the aftermath of the American and French revolutions. The first was that absolutist rule is subject to limits. The monarch derives legitimacy from the consent of the governed. The second was nationalism, wherein a people comes to identify with a common past, language, customs, and territory. Individuals who share such characteristics are motivated to participate actively in the political process as a nation.
Imperialism is the annexation of distant territory (most often by force) and its inhabitants to an empire. Colonialism, which often followed or accompanied imperialism, refers to the settling of people from a home country among indigenous peoples of a distant territory.
The idea behind a balance of power is that states will hesitate to start a war with an adversary whose power to fight and win wars is relatively balanced or symmetrical, because the risk of defeat is high. When one state or coalition of states is much more powerful than its adversaries, asymmetrical war is relatively more likely. A hegemon is any predominant state.
The first and most important outcome of World War II was the emergence of two superpowers–the United States and the Soviet Union–as the primary actors in the international system. The second outcome of the war was the intensification over time of fundamental incompatibilities between these two superpowers in both national interests and ideology. The third outcome was the collapse of the colonial system. The fourth outcome was the realization that the differences between the Soviet Union and the United States would be played out indirectly, on third-party stages, rather than through direct confrontation. Both rivals came to believe that the risks of a direct military confrontation were too great and that the “loss” of any potential ally, no matter how poor or distant, might begin a cumulative process leading to a significant shift in the balance of power. Thus, the Cold War resulted in the globalization of conflict to all continents. Although the United States and Soviet Union retained their dominant positions, new ideas acted as powerful magnets for populations in independent and developing states in Africa, Asia, and Latin America–the new so-called Third World. The Non-Aligned Movement, Pan-Arabism, Pan-Africanism, and Third World socialism developed as reactions to the dominant U.S.-Soviet Union confrontation.
Populism–an appeal to those angry about the decline of traditional values, suspicious of elites, mainstream politics, and established institutions–has emerged as a reaction to globalization. Populism has arisen from, and contributed to, a backlash against international cooperation and globalization. Europeans and Americans have realized that the economic gains from globalization have not been evenly distributed, that wages have stagnated, and that living standards have fallen. They blame the “other”–elites within their own country, other states’ unfair policies, migrants, and refugees; the response has been protectionism and isolationism.
—January 2025
Lance Jones 