United States

The United States occupies a unique position in geopolitical history: a continental-sized nation of 3.8 million square miles with oceanic moats, abundant resources, and no powerful neighbors. With a population of 335 million, a GDP of approximately $28 trillion (roughly 25% of global output), and military spending exceeding $886 billion annually, America remains the world’s preeminent power.

This geographic fortune, combined with economic dynamism and military power, enabled America to become the first truly global hegemon—a role it has played since World War II and struggles to maintain in an era of renewed great power competition with China and Russia.

Geographic Advantages¶

Continental Security¶

The United States enjoys extraordinary geographic protection—advantages that halford-mackinder and other geopolitical thinkers have recognized as historically unique:

Atlantic and Pacific Oceans: The world’s largest moats separate America from potential rivals. The Atlantic is 3,000 miles wide at its narrowest point between the U.S. and Europe; the Pacific stretches 5,000 miles to Asia. No hostile power has successfully invaded American territory since 1812.
Weak neighbors: Canada (population 40 million) and Mexico (130 million) pose no military threat. The U.S.-Canada border, 5,525 miles long, is the world’s longest undefended frontier. This stands in stark contrast to russia, surrounded by potential adversaries, or china, which shares borders with 14 countries including nuclear powers india and Russia.
Resource abundance: The continental United States contains approximately 40 billion barrels of proven oil reserves (supplemented by shale deposits that have made the U.S. the world’s largest oil producer since 2018 at 13 million barrels per day), vast natural gas reserves, 250 years of coal supplies at current consumption rates, 17% of the world’s arable land, the Great Lakes (20% of the world’s fresh surface water), and significant deposits of minerals essential for high-tech manufacturing.
Navigable rivers: The Mississippi River system comprises 12,000 miles of navigable waterways, moving approximately 500 million tons of cargo annually. The Missouri, Ohio, Tennessee, and Arkansas rivers connect the agricultural heartland to the Gulf of Mexico. This internal transport network is larger than all other nations’ navigable waterways combined.
Temperate climate: Suitable for agriculture and habitation across vast territory. The American “breadbasket” produces approximately 35% of the world’s corn and soybeans.

No other great power has ever enjoyed such geographic security. As the French observer Alexis de Tocqueville noted in the 1830s, Americans are “separated from the rest of the world by the ocean.”

The Hemispheric Position¶

The Western Hemisphere has been an American sphere since the Monroe Doctrine (1823), which declared European colonization and intervention in the Americas unacceptable:

No rival great power has established permanent military presence in the Americas. The Soviet deployment of missiles to Cuba (1962) triggered the closest approach to nuclear war in history; the missiles were withdrawn within weeks.
Latin America remained within American influence (if not always control), providing strategic depth and economic partners. American interventions—from Mexico (1914, 1916-17) to Guatemala (1954) to Chile (1973) to Grenada (1983) to Panama (1989)—have enforced hemispheric dominance.
The Caribbean became an “American lake,” with U.S. naval bases at Guantanamo Bay (since 1903), Puerto Rico, and throughout the region.
The Panama Canal (opened 1914, returned to Panama 1999 but with guaranteed American access) linked Atlantic and Pacific, allowing naval forces to shift between oceans without circumnavigating South America.

This hemispheric dominance freed resources for engagement in the Eastern Hemisphere—the opposite of Eurasian powers constrained by nearby rivals. The United States could focus outward because it had secured its rear.

Offshore Positioning¶

America is simultaneously part of the international system and apart from it—the “offshore balancer” that nicholas-spykman and others identified as the optimal strategic position:

Can engage with Europe and Asia without being directly threatened by either. American forces can deploy forward; the American homeland remains secure behind oceanic moats.
Holds the balance-of-power in both regions without being consumed by either. The United States can choose its level of commitment based on circumstances.
Can withdraw (partially) if costs become excessive. Unlike continental powers locked in geography, America has exit options.
Retains the option of intervention that purely continental powers lack. sea-power enables power projection across the globe.

This offshore position makes the United States the ideal Rimland balancer—able to prevent Eurasian hegemony without permanent entanglement. The challenge is maintaining commitment when oceanic distance also enables disengagement.

Historical Trajectory¶

Continental Expansion (1783-1898)¶

The 19th century was devoted to continental consolidation—what historians call “manifest destiny”:

Louisiana Purchase (1803): For $15 million, the U.S. acquired 828,000 square miles from France, doubling national territory and gaining control of the Mississippi River and the port of New Orleans
Westward expansion: The annexation of Texas (1845), the Oregon Treaty with Britain (1846), and the Mexican-American War (1846-48) extended American territory to the Pacific. The 1848 Treaty of Guadalupe Hidalgo added 525,000 square miles (California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado and Wyoming)
Civil War (1861-1865): The bloodiest conflict in American history (620,000-750,000 dead) preserved the Union and eliminated the internal threat of fragmentation. American GDP doubled between 1860 and 1880 despite the war’s destruction
Indian wars (1865-1890): Military campaigns completed continental control, confining Native American populations to reservations and opening the Great Plains to settlement

By 1900, the United States had become a continental power with no serious rivals in the hemisphere. Its population (76 million) exceeded that of any European great power except Russia. Its industrial production had surpassed Britain’s to become the world’s largest.

Rise to Global Power (1898-1991)¶

The 20th century saw America emerge from hemispheric power to world hegemon through four transformative moments:

World War I (1917-1918): American entry tipped the balance in Europe. Over 4 million Americans mobilized; 116,000 died. But the Senate rejected the Treaty of Versailles and the League of Nations, and America withdrew from European commitments—demonstrating the tension between engagement and isolationism that persists today.
World War II (1941-1945): The “arsenal of democracy” produced 300,000 aircraft, 100,000 tanks, and 87,000 ships. American forces fought in Europe, North Africa, and across the Pacific. American casualties totaled 407,000 dead. At war’s end, the United States held approximately 50% of global GDP and possessed the only nuclear arsenal.
Cold War (1947-1991): The containment strategy, articulated by george-kennan in 1947, organized the Western world against Soviet expansion. America maintained approximately 300,000 troops in Europe throughout the Cold War, fought major wars in Korea (36,000 American dead) and Vietnam (58,000 American dead), and built a nuclear arsenal exceeding 31,000 warheads at its peak.
Post-Cold War (1991-2010): The Soviet collapse left America as the sole superpower—what Charles Krauthammer called the “unipolar moment.” Defense spending could have been reduced, but commitments expanded: NATO grew from 16 to 28 members; interventions occurred in Somalia, Bosnia, Kosovo, Iraq, and Afghanistan.

This rise was not inevitable—it required choices to engage rather than remain isolated. Each generation of American leaders faced the same question: Should the United States use its power to shape the world, or retreat behind its oceanic moats?

The Liberal International Order¶

After 1945, America constructed an international order—a system of rules, institutions, and relationships that served American interests while (usually) benefiting others:

Security alliances: NATO (1949) committed the U.S. to defend Western Europe; bilateral treaties extended similar guarantees to Japan (1951), South Korea (1953), Australia and New Zealand (ANZUS, 1951), the Philippines (1951), and Thailand. These alliances now encompass approximately 60 countries and 1.5 billion people.
Economic institutions: The Bretton Woods Conference (1944) created the IMF and World Bank; the dollar became the global reserve currency; the General Agreement on Tariffs and Trade (GATT, 1947) and its successor the WTO (1995) reduced trade barriers. American-designed institutions facilitated an explosion of global trade from approximately $58 billion in 1948 to over $25 trillion today.
Liberal norms: The Universal Declaration of Human Rights (1948), democracy promotion, free markets, and the rule of law became the ideological foundation of the Western order.
American military presence: Bases worldwide—over 750 in approximately 80 countries—and forward deployment of approximately 200,000 troops abroad enabled rapid response and reassured allies.

This order’s durability is now questioned. China challenges its economic principles; Russia contests its security architecture; even allies question whether America will sustain its commitments.

Strategic Culture¶

Exceptionalism¶

American strategic culture reflects a sense of national uniqueness:

A “city on a hill” with a mission to the world
Democratic values as universal, not merely American
Reluctance to accept moral equivalence with other powers
Oscillation between messianic engagement and isolationist withdrawal

This exceptionalism can inspire or blind, depending on circumstances.

Power and Idealism¶

American foreign policy combines hard power with idealistic rhetoric:

Military interventions justified in terms of democracy and human rights
Economic leverage wielded for political purposes
Genuine belief in the universality of American values
Tendency to underestimate others’ resistance to American prescriptions

The gap between professed ideals and actual behavior generates accusations of hypocrisy—sometimes justified, sometimes unfair.

Impatience¶

American strategic culture tends toward:

Desire for quick, decisive results
Discomfort with protracted commitments
Preference for technological solutions to political problems
Difficulty sustaining long-term strategies

This impatience can undermine strategies (like containment) that require patience to succeed.

Military Power¶

Unmatched Capabilities¶

The US military remains without peer in global power projection capability:

Defense spending: Approximately $886 billion in FY2024—39% of global military spending, more than the next nine countries combined. Even in purchasing power parity terms, American military spending exceeds Chinese and Russian spending combined.
Navy: 11 nuclear-powered aircraft carriers (no other nation operates more than 2), 92 cruisers and destroyers, 70 nuclear-powered attack and ballistic missile submarines. The Navy operates approximately 290 combat ships with a combined tonnage exceeding the next 13 navies combined. Carrier strike groups can project power anywhere in the world within days.
Air Force: Over 5,000 aircraft including F-22 and F-35 stealth fighters, B-2 stealth bombers, and approximately 150 tanker aircraft enabling global reach. The U.S. possesses more fifth-generation stealth aircraft than all other nations combined.
Nuclear arsenal: Approximately 1,550 deployed strategic warheads, delivered by a triad of 400 Minuteman III ICBMs, 14 Ohio-class ballistic missile submarines (each carrying 20 Trident missiles), and 66 strategic bombers. The nuclear arsenal, modernizing at a cost of approximately $1.7 trillion over 30 years, remains the ultimate guarantee of national survival.
Technology: Advanced sensors (satellite constellations providing global surveillance), cyber capabilities (U.S. Cyber Command, established 2009), space assets (Space Force, established 2019), and research institutions (DARPA) maintain technological edge.

No other nation can project power globally as America can. China is developing these capabilities; it does not yet possess them.

Global Presence¶

American military forces are stationed worldwide, implementing a forward defense strategy:

Bases: Over 750 overseas bases and installations in approximately 80 countries—from massive facilities like Ramstein Air Base (Germany) and Yokosuka Naval Base (Japan) to small contingency locations
Personnel: Approximately 200,000 troops deployed abroad, including 80,000 in the Indo-Pacific, 100,000 in Europe (increased after Russia’s 2022 Ukraine invasion), and varying numbers in the Middle East
Carrier strike groups: Typically 4-6 deployed at any time, with at least one in the Western Pacific, one in the Middle East, and others rotating through the Atlantic and Mediterranean
Alliance commitments: Mutual defense treaties obligate the U.S. to defend approximately 60 nations containing 1.5 billion people

This presence is simultaneously a source of influence (reassuring allies, deterring adversaries) and a burden on resources (estimated $100+ billion annually for overseas operations and basing).

Challenges¶

American military dominance faces emerging threats that may narrow or eliminate current advantages:

Chinese A2/AD: China has deployed thousands of missiles designed to deny American access to the Western Pacific—the DF-21D and DF-26 “carrier killers,” cruise missiles, and the world’s largest conventional submarine fleet. American carriers may be unable to operate safely within 1,000 miles of China’s coast during a conflict.
Russian nuclear modernization: New delivery systems including the Sarmat ICBM, Avangard hypersonic glide vehicle, and Poseidon nuclear torpedo challenge deterrence stability. Russia has invested heavily in nuclear forces as conventional capability declined.
Asymmetric threats: Terrorism (though diminished since 2001), cyber attacks on critical infrastructure (SolarWinds, Colonial Pipeline), and gray zone operations that fall below the threshold of conventional military response.
Technology diffusion: Precision-guided munitions, drones, and cyber capabilities are spreading to adversaries and non-state actors. The American monopoly on advanced military technology has eroded.
Domestic constraints: Political polarization, debt levels ($34 trillion federal debt), and competing domestic priorities limit military investment. The defense industrial base has atrophied—the U.S. struggles to produce artillery shells at the rate Ukraine consumes them.

Whether American military supremacy can be sustained—particularly in the Western Pacific against China—is the central strategic question of the coming decades.

Economic Position¶

Structural Advantages¶

The American economy retains significant strengths:

Dollar reserve currency: Global demand for dollars provides financing and leverage
Innovation ecosystem: Universities, venture capital, tech companies
Energy production: Shale revolution reduced dependence on imports
Market size: Domestic consumption provides economic foundation

Vulnerabilities¶

Yet vulnerabilities exist:

Debt levels: Federal debt exceeds GDP
Manufacturing decline: Industrial base has eroded
Inequality: Social cohesion threatened by economic disparities
Infrastructure: Aging systems require massive investment

Economic Interdependence¶

Globalization has complicated economic strategy:

Supply chains depend on potential adversaries (China)
Financial systems are interconnected globally
Sanctions and tariffs have costs for the US as well as targets
Decoupling would be expensive and disruptive

The United States is both architect and dependent of the global economic system.

Key Relationships¶

China ¶

The defining strategic challenge:

Economic interdependence alongside strategic competition
Taiwan as the most dangerous flashpoint
Technology rivalry accelerating
No clear end state or stable equilibrium

Managing China while avoiding catastrophic conflict is the central task of American strategy.

Russia ¶

The immediate adversary:

Ukraine conflict as proxy confrontation
Nuclear deterrence remains mutual
European security architecture in crisis
Limited Russian resources constrain long-term challenge

Russia is dangerous but not an existential threat to American power.

Allies¶

Alliance management is critical:

Europe: NATO remains central but requires burden-sharing
Asia: Bilateral alliances with Japan, South Korea, Australia, Philippines
Middle East: Complicated relationships with Israel, Gulf states
Global partners: India, Singapore, and others not formally allied

Allies multiply American power but also create commitments and complications.

Strategic Debates¶

Engagement vs. Restraint¶

A fundamental debate divides American strategists:

Engagement (primacy): - American leadership is essential for international order - Withdrawal would invite aggression and instability - Allies depend on American protection - Retreat is more costly than sustained engagement

Restraint: - Overextension drains resources and invites blowback - Allies free-ride on American protection - Many commitments serve no vital interest - Regional powers can balance local threats

This debate intensifies as relative American power declines.

The Indo-Pacific Pivot¶

The shift toward Asia reflects:

China’s rise as a peer competitor
Economic importance of the Pacific Rim
European allies’ capacity to bear more burden
Middle Eastern entanglements yielding diminishing returns

Whether America can sustain simultaneous commitments in Europe and Asia is unclear.

Democracy Promotion¶

Should America promote its values abroad?

Idealists argue democracy advances American interests and reflects American identity
Realists argue that internal regime type matters less than external behavior
Interventions to promote democracy have a mixed record (Iraq, Afghanistan)
Authoritarian partners are sometimes necessary

The tension between interests and values is never fully resolved.

Future Trajectories¶

Sustained Primacy¶

America maintains its leading position through:

Technological innovation staying ahead of competitors
Alliance relationships adapting to new challenges
Domestic renewal restoring economic dynamism
Strategic discipline focusing on vital interests

Managed Decline¶

Relative decline continues but is managed through:

Burden-sharing with capable allies
Accommodation with rising powers where possible
Prioritization of truly vital interests
Acceptance of a more multipolar order

Contested Decline¶

Alternatively, decline is contested through:

Confrontation with China and Russia
Alliance relationships strained by burden disputes
Domestic division undermining strategic coherence
Risk of major conflict from miscalculation

Conclusion¶

The United States remains the world’s most powerful nation—but its relative position is declining, its commitments exceed its focus, and its domestic cohesion is strained. The question is not whether America will remain a great power, but whether it can sustain the hegemonic role it has played since 1945.

Geography gave America advantages no other nation possesses. History delivered opportunities America seized. The choices made in the coming decades will determine whether American power endures or recedes—and what international order emerges in either case.

Understanding American strategic culture, capabilities, and constraints is essential for comprehending contemporary geopolitics. America remains the indispensable nation—not because the world cannot function without it, but because its choices shape outcomes more than any other power’s. What America does—and what it fails to do—will define the 21st century as it defined the 20th.

Sources & Further Reading¶

American Grand Strategy in the Age of Trump by Hal Brands — Examines how American grand strategy has evolved and the challenges it faces from rising competitors and domestic polarization.
The Hell of Good Intentions: America’s Foreign Policy Elite and the Decline of U.S. Primacy by Stephen M. Walt — A realist critique of American foreign policy establishment and the interventionist consensus that dominated post-Cold War policy.
A World Safe for Democracy: Liberal Internationalism and the Crises of Global Order by G. John Ikenberry — Explains the liberal international order America built and argues for its continued relevance despite challenges.
The Tragedy of Great Power Politics by John J. Mearsheimer — Provides the theoretical framework of offensive realism that has shaped debates about American strategy toward rising powers.