• Liberal philosophy evolved over several centuries, beginning with the Reformation Movement and Enlightenment in the 16th century and continuing into the modern era.
• Throughout its long history, it was shaped by various intellectual minds, trends, and historical forces, making it one of the most enduring traditions in political thought.
• It challenged the spiritual illusions and dogmas of feudal society, replacing them with a scientific, rational, and secular worldview.
• Liberalism promoted modernization, bringing reason, courage, confidence, and self-respect to individuals and societies emerging from feudal constraints.
• Early liberal philosophers like John Locke emphasized the centrality of individual liberty and freedom, which could thrive within a free civil society supported by an encouraging and limited state.
• Later thinkers such as Immanuel Kant, J. S. Mill, and T. H. Green further developed this idea, arguing that individual freedom is best realized within a cooperative political community, notably the state.
• They viewed the state not as a threat to liberty but as an instrument to safeguard and promote individual freedom, provided it remains liberal and non-intrusive.
• This concept of a liberal, encouraging, and less-interfering state inspired scholars in International Relations (IR), leading to the emergence of a liberal tradition in IR theory.
• The liberal approach in IR drew upon and transformed the political ideas of Immanuel Kant, Thomas Jefferson, James Madison, John Stuart Mill, John Locke, David Hume, Jean-Jacques Rousseau, and Adam Smith.
• Liberal Theory (or Liberalism) in International Relations (IR) is associated with several core ideas:
  1. A modern liberal state that encourages human activities for societal development.
  2. State and non-state actors as partners in the development process.
  3. A peaceful state based on democratic principles as the best promoter of a peaceful international order.
  4. Free economic systems within the state and at the international level.
  5. Interdependent national and international orders.
• Liberalism is a product of historical development in the international order.
• Early liberals like Norman Angell and Woodrow Wilson, influenced by the First World War, focused on creating a peaceful international order through cooperation among nation-states.
• This order could be ensured by peaceful, liberal-democratic nation-states that valued individual freedom, liberty, and promoted a competitive economy.
• The early period of liberalism in IR, after the First World War, was called utopian or idealist liberalism because it envisioned an ideal world order free from conflicts and war.
• The rise of Nazi Germany, fascist Italy, and the failure of the League of Nations caused idealist liberalism to lose ground to neo-realist theory emerging in the late 1930s.
• However, liberalism was revived after the Second World War, generating new ideas and enriching the study of international relations.
• In the 20th century, liberal ideas strongly influenced policy-making elites and public opinion in many Western states, especially after World War I, a period in International Relations (IR) often termed Idealism.
• Liberal optimism revived briefly after World War II with the founding of the United Nations, symbolizing hopes for a peaceful international order, but this was soon overshadowed by the Cold War and the resurgence of power politics.
• In the 1990s, Liberalism re-emerged with the proclamation of a New World Order, as Western leaders and thinkers asserted the superiority of liberal democracy over competing ideologies.
• However, after 9/11, the global order once again shifted toward Realism, as the United States and its allies prioritized power consolidation and counter-terrorism, showing the cyclical fortunes of liberal ideas.
• This raises the question of why Liberalism flourishes domestically in Western democracies but faces challenges internationally.
• As Stanley Hoffmann observed, “international affairs have been the nemesis of Liberalism,” since liberal virtues like moderation, compromise, and peace conflict with the realities of international politics, often marked by war and power struggles.
• Realists argue that true law and justice are impossible without a common power, but Liberals counter that power politics itself is shaped by ideas, and therefore, change is possible if those ideas evolve.
• The belief in progress remains central to Liberalism. As Clark (1989) and Doyle (1997) note, Liberalism rests on four key propositions:
  1. Equality of all citizens with basic rights like education, free press, and religious freedom.
  2. Legislative authority derives from the people, and it cannot infringe upon their fundamental rights.
  3. The right to own property is essential to individual liberty and economic independence.
  4. The market economy is viewed as the most efficient system of exchange, free from excessive bureaucratic control.
• Together, these principles highlight the liberal contrast between individual freedom, tolerance, and constitutionalism, and conservatism’s emphasis on order and authority.
• Liberalism is thus both a theory of government and a theory of international relations, grounded in a domestic analogy—just as individuals interact in civil society under law, states too can coexist under international rules and institutions.
• States, like individuals, have different characters—some peaceful, others aggressive—but all enjoy certain natural rights, including non-intervention.
• Liberalism seeks to extend domestic principles such as the rule of law, cooperation, and institutional coordination to the global level, aiming for the domestication of the international system.
• While Realists and Liberals agree that war recurs in the anarchic state system, they differ on causes: liberals attribute war to imperialism, failed balance of power, or authoritarian regimes, not to anarchy itself.
• Liberal thinkers propose remedies such as collective security, free commerce, or world government to reduce conflict and promote order.
• Within Liberalism, there are internal divisions—some advocate a positive conception emphasizing intervention and strong global institutions, while others favor a negative conception that stresses toleration, sovereignty, and non-intervention.

Core Values of Liberalism