Robert Kagan

1. Introduction

Robert Kagan (b. 1958) is an American historian and public intellectual whose work occupies a prominent place in post–Cold War debates about U.S. foreign policy, liberal international order, and the ethics of power. Trained as a historian but active in policy circles and think tanks, he is widely associated with neoconservatism and with arguments for an assertive, values-infused American global role. His writings combine narrative history, strategic analysis, and explicit moral judgment, making them influential not only among policymakers but also in political theory and international ethics.

Kagan is best known for his claim that the contemporary liberal international order is a fragile, historically contingent construction sustained by U.S. power rather than an inevitable stage of human progress. Against “end of history” narratives, he portrays world politics as shaped by enduring forces—ambition, fear, honor, and ideological rivalry—so that American retrenchment could, in his view, usher in greater instability and authoritarian advance.

His major works, including Of Paradise and Power, The Return of History and the End of Dreams, The World America Made, The Jungle Grows Back, and his multi-volume history of U.S. foreign policy, frame recurring questions about hegemony, intervention, and moral responsibility. Proponents see Kagan as a lucid defender of liberal-democratic leadership in a dangerous world; critics regard him as a principal intellectual architect and exemplar of neoconservative militarism.

Because he explicitly links historical interpretation, strategic prescription, and ethical justification, Kagan has become a central reference point in discussions of liberal hegemony, just war, and the dependence of global norms on American primacy.

2. Life and Historical Context

Robert Kagan was born on 26 September 1958 in Athens, Georgia, into an academic family. His father, Donald Kagan, was a prominent historian of ancient Greece at Yale University, and his mother, Myrna Kagan, was an educator. This environment exposed him early to classical treatments of war, empire, and political virtue. He studied history at Yale (B.A., 1980), completed an M.P.P. at Harvard’s Kennedy School, and pursued doctoral work in American history at American University, reinforcing a historically oriented approach to contemporary policy.

Professionally, Kagan served in the U.S. State Department in the 1980s and worked as a foreign policy adviser to Republican politicians, experiences that embedded him in the emerging neoconservative and hawkish bipartisan networks of late–Cold War and early post–Cold War Washington. He later became associated with think tanks such as the Carnegie Endowment for International Peace and Brookings, and wrote regularly in opinion journals and newspapers.

Kagan’s intellectual career unfolded against major geopolitical turning points:

These shifting historical circumstances shaped both the targets and the reception of his arguments about American power, liberal order, and the risks of disengagement.

3. Intellectual Development

Kagan’s intellectual development is often described in phases that track his education, policy work, and subsequent reflection on American power.

Formative Historical Orientation

Influenced by his father’s classical scholarship and his own training at Yale and Harvard, Kagan developed a Thucydidean sensibility: politics as recurring struggle among states driven by fear, honor, and interest. His graduate work in American history oriented him toward long-run continuities in U.S. foreign policy, which later informed Dangerous Nation and The Ghost at the Feast.

Policy Practitioner and Neoconservative Alignment

In the 1980s and early 1990s, Kagan worked at the State Department and advised Republican figures. During this period he aligned with the neoconservative current emphasizing U.S. moral leadership, skepticism toward détente or accommodation with adversaries, and the belief that American power could and should advance democracy. His co-founding in 1996 of the Project for the New American Century (PNAC) crystallized this orientation, linking him to a network advocating increased defense spending and a proactive posture toward perceived threats.

Post–Cold War Theorist of Liberal Hegemony

From the late 1990s through the 2000s, Kagan moved from insider policy roles to a more public, reflective stance. Essays like “Power and Weakness” (2002) and Of Paradise and Power (2003) articulated his influential contrast between American and European strategic cultures. In The Return of History (2008), he explicitly challenged post–Cold War optimism, arguing that great‑power rivalry and ideological conflict were reemerging.

Critic of Liberal Retreat and Internal Erosion

In the 2010s and 2020s, Kagan’s focus shifted toward the fragility of the liberal international order and the vulnerability of liberal democracy within the United States itself. Works such as The World America Made (2012) and The Jungle Grows Back (2019) advanced a more tragic and defensive argument: that existing gains are easily reversible and require continuous American commitment. He also criticized nationalist and populist trends, framing them as internal threats to the liberal project his earlier works had defended externally.

4. Major Works and Themes

Kagan’s major books and essays blend diplomatic history, strategic analysis, and normative reflection. They are often read together as a sustained argument about American power and liberal order.

Across these works, several recurrent themes appear:

• Historical Contingency of Order: Kagan portrays peace and liberal norms as products of specific power configurations, not natural equilibria.
• Intertwining of Power and Ideology: He argues that material power and normative visions co‑constitute international orders, challenging strict separations between realism and idealism.
• American Exceptional Role: Many texts suggest that the combination of U.S. capabilities and liberal-democratic identity gives it distinctive responsibilities.
• Skepticism of Postnationalism: Kagan frequently criticizes European post‑sovereign ideals and institutionalist hopes that law alone can manage security threats.
• Tragic View of Politics: His historical narratives emphasize recurrent conflict, unintended consequences, and the moral burdens of both action and inaction.

These works have provided common reference points for supporters and critics debating the legitimacy and prudence of liberal hegemony.

5. Core Ideas on Power and Liberal Order

Kagan’s core ideas revolve around the relationship between power, liberal values, and the structure of the international system.

Contingent Liberal Order

He advances a contingent liberal order thesis: the post‑1945 system of open markets, alliances, and human-rights norms is not an inevitable result of moral progress but a historically specific product of U.S. primacy. In The World America Made, he argues that absent American military and economic predominance, the institutional architecture and behavioral expectations associated with the liberal order would likely have been far weaker or absent.

Proponents of this reading see it as a historically grounded version of hegemonic stability theory, emphasizing how a dominant power underwrites public goods such as security and global trade. Critics object that it underestimates the autonomous causal force of norms, institutions, and domestic democratic changes.

Power-Dependent Normativity

Kagan maintains that norms and laws are effective only when backed by capable and willing states. He contends that power and ideology are intertwined, such that liberal values spread and are sustained through the actions of powerful liberal states. Supporters interpret this as a corrective to idealist or institutionalist theories that downplay enforcement and deterrence; opponents argue it risks collapsing morality into might and legitimizing hierarchy.

Liberal Hegemony and Its Alternatives

Kagan’s work suggests that a world led by a liberal-democratic hegemon is comparatively more peaceful and prosperous than plausible alternatives, such as multipolar rivalry or authoritarian dominance. He warns that U.S. retrenchment could lead to:

• intensified great‑power competition;
• regional spheres of influence dominated by autocracies;
• erosion of human-rights protections and democratic norms.

Sympathetic readers view this as a realistic appraisal of systemic incentives; detractors see it as overstated, pointing to costs of hegemony, the agency of non‑Western actors, and the possibility of more pluralistic orders.

Persistence of Conflict

Against “end of history” expectations, Kagan asserts in The Return of History that ideological and power conflicts are enduring. This claim supports his view that liberal order requires constant maintenance, not optimistic faith in convergence toward peace.

6. Neoconservatism and the Ethics of Intervention

Kagan is frequently identified as a leading voice in American neoconservatism, particularly in foreign policy. This label refers to a cluster of positions rather than a formal doctrine, and Kagan’s work exhibits many, though not all, of its features.

Neoconservative Orientation

Commonly associated traits in his writings include:

• belief in the universal appeal of liberal democracy;
• moral critique of authoritarian and totalitarian regimes;
• confidence in U.S. capacity to shape international outcomes;
• willingness to use military power proactively.

His role in co‑founding the Project for the New American Century (PNAC) in 1996 and his public advocacy around the Iraq War are often cited as emblematic of this orientation.

Justifications for Intervention

Kagan’s ethical stance on intervention combines universalist claims about human rights with a tragic awareness of risk. He argues that powerful democracies may bear responsibilities to:

• deter or punish aggression;
• prevent mass atrocities;
• support democratic transitions where feasible.

He frequently emphasizes the moral costs of inaction, suggesting that non‑intervention can entail complicity in oppression or genocide. This perspective overlaps partially with the Responsibility to Protect (R2P) doctrine, though Kagan’s focus is more explicitly tied to U.S. leadership and less to multilateral legal procedures.

Preventive and Regime-Change Wars

Kagan has at times defended preventive war and regime change—for example in the context of Iraq—as ethically justifiable when authoritarian regimes pose significant and growing threats and when long‑term dangers outweigh short‑term harms. Supporters regard this as a serious attempt to adapt just war reasoning to novel threats (e.g., WMD proliferation). Critics argue that such reasoning loosens traditional just war constraints on last resort and legitimate authority, risks systematic overestimation of threats, and underestimates unintended consequences.

Internal Diversity and Evolution

Some scholars note shifts in Kagan’s tone over time—from more confident advocacy of transformational interventions to greater emphasis on order maintenance and warning against U.S. withdrawal. Whether this reflects a reconsideration of neoconservative premises or an adaptation to changing circumstances is debated.

7. Methodology: History, Metaphor, and Normative Argument

Kagan’s methodology combines historical narrative, strategic analysis, and explicit moral evaluation, making his work unusual in its crossover between scholarship and policy advocacy.

Historical Narrative as Argument

In Dangerous Nation and The Ghost at the Feast, Kagan employs detailed diplomatic and political history to advance interpretive claims about enduring features of U.S. foreign policy—such as the interplay of ideological mission and strategic interest. He selects episodes (e.g., debates over entry into World War I, interwar isolationism) to illustrate broader arguments about the dangers of withdrawal and the contingency of order.

Supporters view this as rigorous, evidence-based argumentation; critics sometimes describe it as presentist, suggesting that historical episodes are framed to vindicate contemporary preferences about U.S. leadership.

Use of Metaphor

Kagan is known for vivid metaphors that condense complex theses:

• “Mars vs. Venus” in Of Paradise and Power characterizes American and European strategic cultures, with Americans portrayed as more willing to use force and Europeans as more law- and negotiation‑oriented.
• The “jungle vs. garden” imagery in The Jungle Grows Back depicts liberal order as an artificially tended space within a naturally dangerous world.

Proponents argue that these metaphors clarify underlying assumptions about security dependence, strategic culture, and entropy of order. Critics warn that they risk oversimplification, reify stereotypes, and obscure intra‑regional diversity.

Normative Explicitness

Unlike some realist or purely analytical IR literature, Kagan makes his normative commitments explicit: he evaluates regimes, defends liberal democracy as preferable, and assigns responsibilities to powerful states. His approach often moves from:

1. historical description,
2. to diagnosis of causal mechanisms (e.g., deterrence, power vacuums),
3. to prescriptive judgments about what the United States “ought” to do.

Sympathetic commentators see this transparency as a virtue, exposing value-laden premises that often remain hidden; critics argue that normative conclusions are sometimes under-argued relative to the historical complexity he presents.

8. Critiques and Philosophical Debates

Kagan’s work has sparked extensive debate among scholars of international relations, political theory, and ethics.

Realist and Restraint Critiques

Realist and foreign-policy “restraint” thinkers often challenge Kagan’s confidence in liberal hegemony. They contend:

• that he overstates the causal role of U.S. primacy in creating order;
• that he underestimates balancing behavior and self‑help by other states;
• that interventions inspired by his reasoning, such as the Iraq War, illustrate the dangers of hubris and mission creep.

These critics frequently invoke prudential and ethical concerns about unintended harm, fiscal burdens, and domestic liberty.

Liberal and Cosmopolitan Critiques

From more cosmopolitan or institutionalist perspectives, critics argue that Kagan:

• ties normativity too tightly to U.S. power, potentially conflating justice with dominance;
• downplays the emancipatory potential of international law and multilateral institutions;
• insufficiently addresses issues of global distributive justice and the voices of non‑Western societies.

They challenge his skepticism about postnational governance and stress the importance of legal constraints on the unilateral use of force.

Just War and Moral Philosophy Debates

Just war theorists scrutinize his defenses of preventive war and regime change. Some argue that his framing stretches traditional criteria such as just cause, last resort, and reasonable prospect of success. Others note that his attention to the harms of inaction raises difficult questions about negative versus positive duties, complicity, and the ethics of omission.

European and Postcolonial Responses

European commentators often dispute his “Mars vs. Venus” contrast as caricatured, pointing to European military operations and varied national traditions. Postcolonial scholars criticize Kagan’s relative silence on imperial legacies and power asymmetries, interpreting his advocacy of liberal hegemony as a continuation of Western dominance, even if clothed in universalist language.

Overall, Kagan serves as both a leading exemplar and a foil in debates over hegemony, intervention, and the moral status of U.S. power.

9. Impact on Political Theory and International Ethics

Although not a professional philosopher, Kagan has had notable influence on debates in political theory and international ethics, often as a catalyst for clarification and critique.

Shaping Debates on History and Teleology

His challenge to end‑of‑history narratives has prompted theorists to reconsider whether liberal democracy is historically guaranteed or merely a contingent achievement. By stressing the reversibility of liberal gains, he has contributed to a more tragic and less teleological understanding of political progress, influencing discussions about the conditions under which liberal institutions endure or collapse.

Hegemony, Justice, and Global Order

Kagan’s defense of liberal hegemony has become a key reference point in normative analyses of empire and global governance. Political theorists use his work:

• to examine whether hegemonic structures can be morally justified;
• to explore trade‑offs between stability and equality in world order;
• to interrogate how far liberal norms can be disentangled from the power of specific states.

Some argue that he offers a historically informed case for “benevolent” hegemony; others treat his writings as a foil in arguing for more egalitarian or multipolar alternatives.

Ethics of Intervention and Responsibility

In just war theory and global ethics, Kagan’s emphasis on the costs of inaction and the duties of powerful democracies has influenced debates on:

• the Responsibility to Protect (R2P) and its limits;
• the ethics of preventive versus preemptive war;
• how to assess moral responsibility for foreseeable harms resulting from non‑intervention.

His work is frequently cited in discussions of whether and when liberal states should bear special burdens to confront mass atrocities or revisionist powers.

Interdisciplinary Cross‑Fertilization

Because his writings are accessible and widely read in policy circles, they serve as a bridge between academic theory and public discourse. Philosophers and theorists engage Kagan both to understand prevailing policy mindsets and to test normative theories against historically grounded, practitioner‑oriented arguments.

10. Legacy and Historical Significance

Assessments of Kagan’s legacy focus on his role in articulating and defending a particular vision of American global leadership during the post–Cold War and early 21st‑century decades.

Influence on Policy Discourse

Kagan has been regarded as one of the more visible intellectual voices supporting an assertive U.S. foreign policy. His association with PNAC and his arguments around the Iraq War have led many to see him as emblematic of neoconservative thinking in this era. Even critics acknowledge that his formulations—such as “Americans are from Mars and Europeans are from Venus”—entered mainstream debates and shaped how policymakers and publics framed questions of burden-sharing, intervention, and alliance politics.

Place in Intellectual History

In intellectual histories of U.S. foreign policy, Kagan is often positioned alongside figures like Francis Fukuyama and Samuel Huntington as a key contributor to grand narratives about the post–Cold War order. His multi‑volume historical account of American foreign policy situates contemporary disputes within a longer tradition of U.S. engagement with the world, reinforcing the idea that current controversies echo earlier conflicts over isolationism, expansion, and moral purpose.

Contested Significance

Interpretations of his historical significance diverge:

• Some scholars argue that Kagan helped preserve support for liberal internationalism at a time of growing skepticism, offering a coherent, historically informed defense of engagement.
• Others contend that his legacy is tightly bound to controversial interventions and that subsequent disillusionment with these policies has diminished the appeal of his brand of liberal hegemony.

Ongoing Relevance

As debates continue over U.S. retrenchment, China’s rise, Russian assertiveness, and the resilience of liberal democracy, Kagan’s warnings about the fragility of order and the potential return of a geopolitical “jungle” remain widely discussed. Whether his work is ultimately seen as a prescient defense of a fading order, a rationale for overreach, or a complex mixture of both is an open question in ongoing historical and philosophical assessment.