Key points

1. Geographic distance and the current state of military technology interact to favor defense while diminishing the threat of conquest. The stopping power of water in particular obstructs the ability of even the most powerful states to project power overseas.
   
   
2. Proximate land powers are the most likely to engage in security competition and conflict, while distant or sea powers are relatively isolated from potential adversaries. This strategic insularity is even greater if a state has a large and diversified economy and the resources to be relatively self-sufficient.
   
   
3. The United States is separated from other great powers by thousands of miles of ocean to both its east and west, and is the most powerful, prosperous, and secure state in the world.
   
   
4. However, many of the same conditions which make the United States secure also make it difficult to project power, carry out wars far abroad, and maintain military primacy on land in Eurasia.
   
   
5. The United States should both embrace its abundance of security and accept the limits to its offensive power, using its position as a continent-sized maritime power to act as an offshore balancer rather than a hegemon on the flanks of the Eurasian landmass.

The geography of restraint

Distance continues to provide benefits to defense while raising the costs of offense, especially for those states seeking to sustain territorial conquest. The United States is uniquely favored by its geography, which contributes enormously to its abundant security. At the same time, however, the combination of geographic distance and developments in military technology are making it harder for the United States, or any state, to project power to distant regions of the world. Fortunately, these circumstances also make the pursuit of regional hegemony and aggression by rivals less achievable, rendering threats to vital U.S. security interests even more remote. The same factors that complicate the United States’ ability to carry out large land wars in Eurasia, in other words, also diminish the threats the United States might conceivably face that would justify such a commitment.

The combination of geography and technology should thus make the United States more judicious in its military commitments, while also encouraging optimism regarding threats that adversaries might pose. This is good news the United States should embrace by adopting a grand strategy of restraint.

The following explainer will first review some concepts in geopolitics: namely, how proximity and land borders tend to produce security competition; how geography and national resources interact with the distribution of power among states; and how distance continues to be—and in some ways may be more than ever—an obstacle to power projection abroad. Next, it will examine the particular geopolitical circumstances of the United States and how geography has both benefited and frustrated U.S. grand strategy over the past century. Finally, it will explain how these circumstances lend themselves to a grand strategy of restraint, which leans into the United States’ geographic advantages, its unique position as a maritime power insulated from the exigencies of great power competition on the Eurasian landmass, and the advantages conferred on defense by developments in military technology.

Geopolitics and security

The regional security environment

The first and most important region of strategic significance to a state is its own. Nothing matters more to a state than its ability to preserve its sovereignty, the safety of its domestic population, and its territorial integrity.

Proximity between states magnifies their mutual vulnerability by putting their dearest interests within range of each other’s military forces at their highest concentration and effectiveness. This is particularly true of states which share land borders. Some geographic features are more conducive to offense than others, and it is easier for large armed forces to move over land than by sea or air.¹ Open flatlands in particular allow for the rapid movement of tanks and infantry and are therefore best suited to modern offensive warfare.

By contrast, bodies of water, mountain ranges, and extreme climatic zones act as obstructions against invasion and provide states with natural defensive buffers. Oceans and seas pose particularly formidable obstacles to the mass movement of troops and equipment across long distances onto foreign shores, a phenomenon John Mearsheimer calls “the stopping power of water.”¹ Since natural barriers have acted over centuries as obstacles to both voluntary migration and invasion, many states’ political borders are formed along natural boundaries of this kind.

Proximate land powers are more likely to go to war with one another than distant or sea powers, all things being equal. States with large or numerous land borders lacking natural boundaries can be quite vulnerable themselves and/or quite threatening to their neighbors, depending on the relative distribution of power between them. Land powers thus often maintain large armies and deep defenses along their borders. Since it is preferable to fight on someone else’s territory rather than your own, even states whose intentions are limited to territorial defense must often build the capability to take land outside of their borders and bring the fight to their enemies’ home.

Proximity also causes states to interact more frequently in general and have overlapping concerns over their shared periphery, engendering disputes which over time can escalate to the level of armed conflict. A common source of conflict between neighboring states regards political borders and shared waters—examples include the disputed Kashmir region, the Senkaku/Diaoyu islands, and the South China Sea, among countless other cases throughout history. Because proximate states’ mutual vulnerability often encourages them to distrust, fear, and arm themselves against one another, these disputes become more intractable and subject to the “first mover” incentive to strike the other preventatively before being struck themselves.³

While vulnerability to attack is magnified by proximity, distance imposes barriers to attack. As distance increases, the mass and coordination of forces that can be concentrated at a decisive point and time diminishes. This negative relationship between distance and military effectiveness was termed “the loss-of-strength gradient” by Kenneth Boulding.⁴ Since warfare generally favors defense, the ability to bring a sufficient number of attacking forces (the classic rule of thumb is a 3:1 ratio of attackers to defenders) safely across long distances with the resources to conduct a protracted campaign is a colossal and complex undertaking.⁵ The costs required to “get there the fastest with the mostest” increases with distance, while the resources and willingness to sustain those costs diminishes.

An old military adage states that “amateurs talk strategy, professionals talk logistics.” The distance a military must traverse extends the length of the supply lines which link them to their base of support. These are the arteries that keep military forces alive, both figuratively and literally. As these lines of communication become more extended, reinforcements and resupply arrive more slowly, disruptions and bottlenecks become more likely to compound, and supply lines become more vulnerable to interdiction by the enemy. Protecting these lines of communication becomes a major task in itself.

By contrast, defenders benefit from interior lines of communication, which allow for shorter and less vulnerable routes of reinforcement, resupply, and retreat to home bases, and for the relatively rapid redeployment of forces along a front as needed. Attackers can most easily traverse open terrain and seas, yet in doing so they lack cover or refuge, assets which defenders possess in abundance and have the time and resources to augment.

The global distribution of power

Force is the arbiter of last resort between states, and the military power needed to exert force is dependent upon the ability of a state to mobilize its economic power—crucially, its industry, technology, natural resources, and population.⁶

The distribution of these capabilities among states is uneven. Since states are territorial in scope, concentrations of industrial and military power are also distributed unevenly with regard to geography. The largest economies in the world, and therefore the states with the most power potential, are mainly concentrated in North America, East Asia, and Western Europe.

Aggressors have historically sought to maximize their relative power and security by conquering other states. Conquest theoretically allows the conqueror to both exploit the economic potential of the vanquished—harnessing their industry, technology, natural resources, labor force, and tax revenues—and to eliminate them politically as rivals or sources of military resistance.⁷

Conversely, the ability of states to defend themselves depends on preventing a single more powerful state from accumulating overwhelmingly large concentrations of economic and military power—becoming a “hegemon.” Security-seeking states thus attempt to prevent the emergence of hegemons in their regions and tend to pool forces with other states to counter—or “balance” against—powerful threats.⁸

Natural resource deposits are an important driver of economic development and hence military power, making them a source of interstate competition. For example, the centrality of oil as an energy source over the past century has made the vast petroleum reserves of the Persian Gulf a geostrategic priority for great powers. Likewise, states seek to maintain access to critical raw material inputs: for example, many are (perhaps overly) fearful the West is too dependent on rare earth elements supplied primarily by China.⁹

States may also gain advantages by seizing strategic geographic features, including narrow maritime passages which can become chokepoints to control commerce and navigation in wartime. Examples of this include the Panama Canal, the Strait of Malacca, and the Strait of Hormuz. Another example of strategic ground is illustrated by the importance which the island nations of Great Britain and Japan have historically placed upon preventing a hostile power from controlling, respectively, the Low Countries and the Korean Peninsula, the points across which their sea buffers are the narrowest.

The continuing tyranny of distance

Having already stated that distance works to the benefit of defense and to the detriment of offense, it’s now important to examine in more detail why technological advancements have not eliminated the importance of distance as is often claimed—and why they have in some ways only reinforced it.

In his important work on the continuing relevance of geography in strategic affairs, Patrick Porter draws a distinction between “physical distance” and “strategic distance.”¹⁰ The ability to move in time and space across physical distance has been compressed by modern technological advances in transportation and telecommunications. But, as Porter notes, the same technology has actually increased the “strategic distance” over which states attempt to project military power by forcing them to contend with more powerful and sophisticated weapons across a more extensive range in the face of resistance.¹¹ The circumstances which facilitate rapid communication and transport between cooperating partners are not the same as those which apply in a state of conflict, where opposed wills and forces contend.

Most conventional wars still come down to the need to bring ground troops to bear on an opponent. It is true enough that missiles carrying destructive payloads can be launched from one continent to another with remarkable precision in a matter of minutes, satellite networks can provide seeming ubiquitous surveillance across the globe, and advances in data processing can accelerate real-time decision-making. But while unimaginable destructive power can be rapidly delivered across the world via intercontinental missiles, this capability mainly serves the purpose of deterring, coercing, or punishing an adversary, as aggressors gain little by reducing the territory they wish to conquer to a smoldering wasteland, especially if reciprocation is likely. Furthermore, the experience of strategic bombing from World War II through the First Gulf War to the present has shown that airpower alone is often ineffective at forcing a determined enemy to surrender, let alone to accomplish the “better peace” for which the war is presumably being fought in the first place.¹²

Therefore, when U.S. troops are committed to fight in Europe, Asia, or the Middle East, they must be transported overseas thousands of miles en masse. While technically faster than maritime travel, air transport remains more limited in the personnel and cargo it can move in a given period, and therefore ships remain the most efficient means of conveying troops and equipment across large bodies of water.¹³ Making sure these troops arrive safely to base and are not destroyed en route by submarines, antiship missiles, enemy aircraft, or sea mines is itself a major task.

For example, technological advances in precision-guided munitions allow China’s land-based assets to accurately hit targets as far from its coastline as the U.S.-administered island of Guam, dramatically increasing the “strategic distance” that U.S. forces would have to traverse under fire to reach the battle space, say, in a fight over Taiwan—which is about 100 miles off the coast of mainland China, but 5,000 miles from Hawaii and 7,000 miles from San Diego.¹⁴ Meanwhile, U.S. forces stationed in the West Pacific, such as those on the Japanese island of Okinawa, could become preemptive targets for China’s missile forces, turning the supposed benefits of the United States’ “forward posture” (military bases near the action) on their head. As the designation “anti-access/area denial” suggests, the entire function of these capabilities is to keep a third party at a greater “strategic distance”—to prevent them from being able to reach the theater and intervene effectively in time.

Mass movement is even harder for forces undertaking an amphibious invasion of an enemy’s shoreline. First, to deliver troops to land, the attacker must gain control of the air and sea, and must wear down the enemy’s land-based defenses and disrupt its coordination and cognizance of the battlefield. Smaller bodies of water allow for land-based aircraft to be deployed, albeit with a limited radius of action before they must return and refuel. Deploying aircraft over larger bodies of water requires aircraft carriers—huge and expensive platforms requiring not only lots of manpower to crew but their own protective entourage of additional warships. Once delivered to shore, amphibious forces must debark their troops and cargo under heavy fire, fighting their way up beaches lacking cover and usually studded with mines, barbed wire, and other obstructions. Only after having secured a beachhead does the ground fight begin in earnest, on the enemy’s home turf where that enemy is most determined to resist.

Distance can therefore offset imbalances in material capabilities or aggregate military power, allowing relatively weak defenders to hold off more powerful but distant aggressors.

But distance not only offsets the balance of power, it also directly affects the balance of resolve. Defenders are often fighting for hearth and home, while attackers’ objectives tend to be less vital the farther they are from home. The “asymmetry of effort,” to use Porter’s words, that attackers must endure becomes even more costly and difficult to sustain given the “asymmetry of interest” that often favors the defender.¹⁵

Geopolitics and U.S. grand strategy

The United States’ geostrategic position

The United States has an ideal geostrategic position. It is the wealthiest and most powerful state in the world. It is the only great power in the Western Hemisphere and the only regional hegemon in modern history. It has a vast, resource-rich interior and a large population, the results of both ruthless expansion and two centuries of large-scale immigration. The United States has only two political land borders to guard, and its neighboring states—perhaps in large part as a result of its overwhelming power position—are friendly, deferential, and its main trading partners.¹⁶ Indeed, its northern neighbor, Canada, is not only a treaty ally but is integrated into the United States’ aerospace defense system, NORAD.

To its east and west, the United States is flanked by the Atlantic and Pacific oceans, separating it by thousands of miles in either direction from the other major military and economic powers of the world. These oceans are both the greatest natural barriers against external assault in the world and superhighways for international commerce. The United States has unobstructed access to the hemisphere’s sea lanes, including the Panama Canal, which connects U.S. shipping to both oceans.

The United States is abundant in natural resources and is incredibly food-, energy-, and mineral-secure.¹⁷ The United States is the largest producer in the world of both oil and natural gas.¹⁸ It’s a net total energy exporter, and has technological advantages that make it highly competitive in emerging renewable energy sectors.¹⁹ Two states within the Western Hemisphere, Venezuela and Canada, respectively, have the world’s first and third largest oil reserves; exports from either country to the United States are relatively invulnerable to interdiction by a great power rival, making the United States even more energy-secure.²⁰ The United States is also rich in deposits of various minerals and metals, including untapped deposits of rare earth elements should it need them.²¹

While one of the world’s most active trading nations, the United States is nonetheless better insulated from disruptions to trade than virtually any other. If forced, it is more capable of economic self-sufficiency than most other states, featuring one of the lowest trade-to-GDP ratios in the world, relying less than most developed nations on foreign inputs and markets, and dominating the high value-added “commanding heights” of global value chains it is integrated into.²² Moreover, the United States’ trade relations are nearly evenly split between Europe, East Asia, and the rest of the Western Hemisphere, making it very difficult in a major wartime scenario for the United States to be cut off entirely from trade and economically strangled.²³ By contrast, the other largest trading nation in the world, China, is more dependent on foreign trade and energy imports, and its trade is less diversified across regions globally.²⁴

The United States as an offshore balancer in the twentieth century

It is useful to think of the United States in a geostrategic sense as an “island” in relation to the supercontinent of Eurasia. This makes the U.S. position analogous to that of Great Britain’s relation to continental Europe during the heyday of intra-European great power competition. The natural tendencies of both the United States and the United Kingdom as great powers have therefore been to act as “offshore balancers” vis-à-vis the continental great powers.²⁵

Despite having achieved its favorable power position within the Western Hemisphere by the end of the nineteenth century, concerns regarding the shifting balance of power in Eurasia (particularly the decline of Britain as a balancer among the European great powers and the rise of Germany) led the United States into an increasingly active and ultimately central role in global great power politics.

U.S. grand strategy in the twentieth century was based on two major priorities. The first was to prevent a single state or bloc from dominating the core industrial regions of the Eurasian landmass—especially Western Europe and East Asia—which might allow a hostile state to accumulate enough power to threaten the United States within the Western Hemisphere.²⁶ Initially, the United States sought this goal by “passing the buck” to regional powers to balance against emergent threats and intervening only when the balance failed to hold, as during the two World Wars. After World War II, the destruction of Europe and Japan brought the United States into a sustained “onshore” commitment to deter the Soviet Union and rebuild its allies’ economies, though the strategic logic remained similar.²⁷

The second goal, which emerged after World War II, was to prevent a disruption to the supply of Persian Gulf oil, the primary energy source for the industrialized world. While initially relying on Britain and then Iran to manage the balance of power in the region, the United States also took an increasingly direct role following the Iranian Revolution in 1979, later establishing permanent military bases after the First Gulf War of 1990-1.²⁸

The folly of pursuing global hegemony

After the collapse of the Soviet Union, the fundamental logic of U.S. grand strategy changed. Rather than seeking to maintain a balance of power in Eurasia, the United States endeavored to preserve its post-Cold War position of military primacy and to establish its hegemony on a global scale.²⁹ The United States expanded its military commitments in Europe and Asia and established a new presence onshore in the Middle East, the latter leading to a string of ill-fated wars to reshape the region according to U.S. policymakers’ designs.³⁰

The United States’ post-Cold War grand strategy leaned heavily on the assumption that U.S. technological supremacy (the “revolution in military affairs”) would allow it to occupy territory and populations in faraway parts of the world, without having to commit the resources that distant military endeavors normally demanded.³¹ To the extent that distance still blunted power projection, so it was argued, the United States would need to rely on its global archipelago of forward military bases.³² But even with unprecedented capabilities, the United States was forced to confront the limits of its military power. The post-9/11 wars in the Middle East proved to be not only costly but fruitless, thwarted by some of the least wealthy and powerful societies on the planet.³³ Indeed, the relative costs of wars in the periphery seem to have risen conspicuously in recent decades.³⁴

There are at least two salient reasons why U.S. military-technological supremacy failed to overcome geography. The first is that advances and diffusion of military technology benefit defense as well as offense, with the balance favoring the former the more distance increases. The second is the durability of local political-cultural identification, which as a shorthand can be called “nationalism.” Nationalism creates asymmetry between the interests of local populations, on the one hand, and the far more tenuous interests of the distant United States in their affairs, on the other.

The “strategic distance” over which the United States must project power has grown. Far more formidable than the Taliban or Iraqi insurgents, great or regional powers like China, Russia, and Iran can counter the United States at a lower cost in their own backyards, altering the costs and risks ratio for the United States to intervene in a local contingency. This is especially true if U.S. interests are conditional enough for it to not commit the full weight of its national resources to the fight. The United States’ grand strategy should be recalibrated to reflect a more rigorously prioritized set of interests and more modest expectations regarding the political outcomes that can be achieved by the use of U.S. military power abroad.

Geography and technology favor restraint

The limits to power projection overseas are a blessing in disguise for the United States. While strategic distance and the stopping power of water make it difficult for the United States to intervene across the oceans, they make it even more difficult for Eurasian great powers—or possibly even a hegemon—to threaten the United States. This is good news, since the latter condition removes the main security rationale for the United States to project power onto the Eurasian rimland in the first place. Moreover, the series of island chains which characterize East Asia and the West Pacific make it difficult for the United States’ most formidable competitor, China, to pursue hegemony within its own region, diminishing concerns that China might accumulate enough power through conquest to project overwhelming power outside its borders. Were the United States to scale back its forward military presence in Eurasia, it would appear to be less of a threat to others, and consequently others would appear less of a threat to it—a boon for U.S. peace and security.

Slim chances of a Eurasian hegemon

Neither China nor Russia is well-positioned to pursue concerted territorial expansion, let alone to achieve regional hegemony and project power into the Western Hemisphere.

In the near term, both face the problem that the current military-technological balance seems to favor defense, a condition that offense-defense theorists call “defense dominance.”³⁵ This has been dramatically demonstrated by the war in Ukraine, where both sides have been able to blunt the other’s attempts at an offensive breakthrough by establishing defenses in depth. While a continued war of attrition may eventually wear down Ukrainian forces to the point that Russia can advance, so far the battle lines have barely changed since the beginning of the war, held fast by dense belts of mines, drones, and artillery.³⁶

China, which is more powerful than Russia and a more plausible candidate for regional hegemony, also faces a more challenging geography with which to contend. Just as defense dominance provides an advantage to China against the United States in the West Pacific, it helps balance the scales between China and its weaker neighbors. The geography of East Asia is not conducive to territorial expansion, populated as it is by islands that would have to be taken by the kind of difficult amphibious operations described above.³⁷ These states can also easily and rapidly acquire anti-access/area denial capabilities of their own, providing a capable defense of their home islands and preventing China from dominating the South China Sea.³⁸ In order to secure oil imports from the Gulf, China’s ships must cross the Indian Ocean and a number of maritime chokepoints, putting them at risk of interdiction in a major conflict.³⁹ China’s size also curses it with extensive land borders to worry about, including with regional powers like Russia to its north and India to its south.

In the Middle East, there is a rough equilibrium of power without the added U.S. presence.⁴⁰ Not only is Iran balanced by its regional rivals, but global oil supplies are both difficult to critically disrupt and of declining importance given the growing number of alternative energy sources.⁴¹

Furthermore, it has been plausibly argued that the value of conquest as a source of cumulative power is diminishing, and that the nuclear revolution makes the threat from a regional hegemon irrelevant.⁴² While the United States may wish to hedge against overoptimism and avoid testing these propositions in practice, there remains a serious case that the prospect of a rival hegemon is more remote and less threatening than in prior eras, especially to distant nuclear-armed powers like the United States.

The strategic insulation of the United States

The same difficulties the United States faces attempting to project power overseas would also be faced by a Eurasian power attempting to attack the Western Hemisphere. The United States, which has the most capable military in the world, would in such a scenario gain all the advantages of defense off its shores and would likely prove more economically resilient than other great powers. Moreover, its large nuclear arsenal makes it unlikely that even another nuclear armed state could successfully coerce the United States, let alone undermine its sovereignty or survival.

The United States’ distance from the great powers of Eurasia should act to mutually reassure. There is historical evidence that distance and the stopping power of water serve to assuage continental land powers that “insular” maritime states—like the United States and United Kingdom—pose a reduced threat and tend toward the status quo in their interests.⁴³ This tendency helps explain in part why states proved relatively slow to counterbalance the United States after the Cold War.⁴⁴

In light of this, it is remarkable to consider how extreme the United States’ proclivity for regime change, military intervention, and an expanding forward posture over the past few decades have been in order to overcome the natural palliative provided by its geography and encourage other states to counterbalance it. The main effect of the United States’ post-Cold War aggressiveness has been to unite adversaries. Notably, this includes China and Russia, which are not only the other two great powers in the international system, but whose own geographical proximity, shared land borders, and competing ambitions for influence in Central Asia should make them natural rivals. Instead, they have converged in an anti-American entente, while also operating in close cooperation with regional powers like Iran and North Korea.

Given the unparalleled security afforded by its geography and relative power position, the United States would benefit by abandoning its pursuit of global primacy and instead adopting a more rigorously prioritized grand strategy of restraint. While the possibility of a Eurasian hegemon is remote and its consequences for the United States are diminished by nuclear weapons and the stopping power of water, it remains a prudent strategic hedge for the United States to remain observant of the balance of power in Eurasia, and to help maintain that balance from a distance.⁴⁵

First, the United States should return to being an offshore balancer, passing the buck to regional powers in order to reestablish a stable local equilibrium. The United States would steadily withdraw its forward deployed forces from Eurasia, and instead provide material support by helping to arm local powers as necessary. This would also allow the United States to gain greater diplomatic flexibility, maximizing its leverage with both partners and competitors in what looks to become a more dynamic multipolar environment.

Second, the United States should retain its “command of the commons” by keeping an edge in the related sea, air, space, and cyber domains.⁴⁶ This military strategy emphasizes the United States’ persistent advantages—its maritime buffers, its technological innovation, etc.—while refraining from distant onshore commitments of land forces, where the United States is least likely to be effective. Maintaining a superior ability to contest the media of transportation and communications would allow the United States in a major contingency to secure its commerce and resupply its allies—aiding local balancing—while threatening its adversaries’ ability to do the same. U.S. defense planning should privilege the Navy—particularly its submarine fleet—and retain the ability to control or deny vital maritime chokepoints.⁴⁷

Third, the United States should maintain a nuclear deterrent robust enough to convince a risk-acceptant adversary that they will not be able to escalate their way to victory, while being willing to engage in reciprocal arms control agreements as circumstances allow.

In sum, the United States’ distance from the other great powers, its geographic and resource advantages, and the benefits conferred on defense by the current military-technological conjuncture provide the United States with a relatively benign security environment. There are neither compelling security imperatives nor credible means for the United States to enforce a system of global hegemony by projecting power far from home into the backyards of other great powers. The United States can play to its advantages, maximize its leverage, and best sustain its power position over the long term by decreasing its military role in Eurasia and returning to its historical role as an offshore balancer.

In his “Lyceum Address” of 1838, Abraham Lincoln celebrated the United States’ insulation from external danger:

Shall we expect some transatlantic military giant, to step the Ocean, and crush us at a blow? Never! All the armies of Europe, Asia and Africa combined, with all the treasure of the earth (our own excepted) in their military chest; with a Buonaparte for a commander, could not by force, take a drink from the Ohio, or make a track on the Blue Ridge, in a trial of a thousand years.⁴⁸

In a similar vein, Jean Jules Jusserand, the French Ambassador to the United States from 1902 to 1924 remarked that: “America is the most favored of all the nations. To the north, she has a weak neighbor. To the south, another weak neighbor. To the east, fish. To the west, fish.”⁴⁹ From the perspective of a Frenchman during World War I, the United States’ ability to stand aloof from European power politics must have been enviable indeed. In the 21st century, the United States continues to be the most favored of all nations. Its geography can be among its greatest blessings—provided it is taken advantage of by policymakers.

Endnotes

¹ John J. Mearsheimer, The Tragedy of Great Power Politics (New York: W.W. Norton, 2001), 83–137.

² Mearsheimer, The Tragedy of Great Power Politics, 114–128. While Mearsheimer is widely known as the leading theorist of offensive realism, some have noted that “the stopping power of water” is essentially a defensive realist concept. See Barry R. Posen, “The Best Defense,” The National Interest, 67 (Spring, 2002), 119–126; Christopher Layne, The Peace of Illusions: American Grand Strategy from 1940 to the Present (Ithaca: Cornell University Press, 2007), 19–20.

³ For a discussion of the causes of war rooted in the security dilemma, see Stephen Van Evera, Causes of War: Power and the Roots of Conflict (Ithaca, NY: Cornell University Press, 1999), especially 35–72.

⁴ Kenneth E. Boulding, Conflict and Defense: A General Theory (New York: Harper and Row, 1962), 79, 230–2, 245–7.

⁵ John J. Mearsheimer, “Assessing the Conventional Balance: The 3:1 Rule and Its Critics,” International Security 13, no. 4 (Spring, 1989): 54–89.

⁶ For a classic study of the relationship between economic and military power, see Paul Kennedy, The Rise and Fall of the Great Powers: Economic Change and Military Conflict from 1500 to 2000 (New York, NY: Random House, 1987).

⁷ Peter Liberman, Does Conquest Pay? The Exploitation of Occupied Industrial Societies (Princeton, NJ: Princeton University Press, 1996).

⁸ Stephen M. Walt, The Origins of Alliances (Ithaca, NY: Cornell University Press, 1987); Kenneth N. Waltz, Theory of International Politics (Long Grove, IL: Waveland Press, 1979), 103–128, 161–193.

⁹ For a study of U.S. interventions in Latin America to maintain access to raw materials, see Stephen D. Krasner, Defending the National Interest: Raw Materials Investments and U.S. Foreign Policy (Princeton, NJ: Princeton University Press, 1978). On China’s rare earths, see Eugene Gholz, “Rare Earth Elements and National Security,” Council on Foreign Relations, October 2014, https://www.cfr.org/sites/default/files/pdf/2014/10/Energy%20Report_Gholz.pdf.

¹⁰ Patrick Porter, The Global Village Myth: Distance, War, and the Limits of Power (Washington, D.C.: Georgetown University Press, 2015), 18–58.

¹¹ Porter, The Global Village Myth, 148–193.

¹² Robert A. Pape, Bombing to Win: Air Power and Coercion in War (Ithaca, NY: Cornell University Press, 1996).

¹³ Porter, The Global Village Myth, 10.

¹⁴ Stephen Biddle and Ivan Oelrich, “Future Warfare in the Western Pacific: Chinese Antiaccess/Area Denial, U.S. AirSea Battle, and Command of the Commons in East Asia,” International Security 41, no. 1 (Summer 2016): 7–48; Mark F. Cancian, Matthew Cancian, and Eric Heginbotham, The First Battle of the Next War: Wargaming a Chinese Invasion of Taiwan (Washington, D.C.: Center for Strategic and International Studies, January 2023).

¹⁵ Porter, The Global Village Myth, 152.

¹⁶ International Trade Administration, “U.S. Goods Trade with Global Partners,” accessed November 17, 2023, https://www.trade.gov/data-visualization/us-goods-trade-global-partners.

¹⁷ World Bank, “Arable Land (hectares),” accessed November 17, 2023, https://data.worldbank.org/indicator/AG.LND.ARBL.HA?most_recent_value_desc=true; World Bank, “Agricultural Land (sp. Km),” accessed November 17, 2023, https://data.worldbank.org/indicator/AG.LND.AGRI.K2?most_recent_value_desc=true.

¹⁸ U.S. Energy Information Administration, “Frequently Asked Questions: Which Countries are the Top Producers and Consumers of Oil?,” accessed May 10, 2024, https://www.eia.gov/tools/faqs/faq.php?id=709&t=6; Energy Institute, Statistical Review of World Energy 2023, https://www.energyinst.org/__data/assets/pdf_file/0004/1055542/EI_Stat_Review_PDF_single_3.pdf, 30–31.

¹⁹ U.S. Energy Information Administration, “U.S. energy facts explained,” accessed April 16, 2023, https://www.eia.gov/energyexplained/us-energy-facts/imports-and-exports.php.

²⁰ CIA Factbook, “Crude Oil – Proved Reserves,” November 17, 2023, https://www.cia.gov/the-world-factbook/about/archives/2021/field/crude-oil-proved-reserves/country-comparison.

²¹ CIA Factbook, "Field Listing - Natural Resources," accessed May 21, 2024, https://www.cia.gov/the-world-factbook/field/natural-resources/; Statista, “Leading Countries Worldwide Based on Natural Resource Value as of 2021,” accessed May 7, 2024, https://www.statista.com/statistics/748223/leading-countries-based-on-natural-resource-value/; Jeremy Hsu, “Don’t Panic About Rare Earth Elements,” Scientific American, May 31, 2019, https://www.scientificamerican.com/article/dont-panic-about-rare-earth-elements/; Gholz, “Rare Earth Elements and National Security.”

²² World Bank, “Trade (% of GDP),” accessed April 17, 2023, https://data.worldbank.org/indicator/NE.TRD.GNFS.ZS?most_recent_value_desc=false; World Trade Organization, “United States: Trade in Value Added and Global Value Chains,” accessed July 25, 2023, https://www.wto.org/english/res_e/statis_e/miwi_e/US_e.pdf; World Trade Organization, “Trade in Value Added and Global Value Chains: Country Profiles Explanatory Notes,” accessed February 20, 2024, https://www.wto.org/english/res_e/statis_e/miwi_e/explanatory_notes_e.pdf; OECD, ICIO-TIVA Highlights: GVC Indicators for the United States,” accessed February 20, 2024, https://www.oecd.org/industry/ind/CN2023_USA.pdf; OECD, “Gross Output Flows in Global Value Chains,” accessed February 20, 2024, https://www.oecd.org/industry/ind/gross-output-linkages-in-global-value-chains.htm.

²³ Office of the United States Trade Representative, “Countries and Regions,” accessed April 17, 2023, https://ustr.gov/countries-regions.

²⁴ World Bank, “Trade (% of GDP),”; World Trade Organization, “China: Trade in Value Added and Global Value Chains,” accessed February 20, 2024, https://www.wto.org/english/res_e/statis_e/miwi_e/CN_e.pdf; ECD, ICIO-TIVA Highlights: GVC Indicators for China,” accessed February 20, 2024, https://www.oecd.org/industry/ind/CN2023_CHN.pdf; U.S. Energy Information Administration, “China,” accessed February 20, 2024, https://www.eia.gov/international/analysis/country/CHN; Observatory of Economic Complexity, “China,” accessed February 20, 2024, https://oec.world/en/profile/country/chn.

²⁵ For a discussion of Great Britain and the United States as offshore balancers, see Mearsheimer, The Tragedy of Great Power Politics, 234–266.

²⁶ George F. Kennan, American Diplomacy, 1900–1950 (Chicago: University of Chicago Press, 1951), 4–5; Nicholas J. Spykman, America’s Strategy in World Politics: The United States and the Balance of Power (New York: Harcourt, Brace, and Company, 1942), especially 411–457; Nicholas J. Spykman, The Geography of the Peace, ed. Helen R. Nicholl (New York: Harcourt, Brace, and Company, 1944); Hans J. Morgenthau, In Defense of the National Interest: A Critical Examination of American Foreign Policy (New York: Alfred A. Knopf, 1951), 5–7.

²⁷ John Lewis Gaddis, Strategies of Containment: A Critical Appraisal of American National Security Policy During the Cold War, rev. and expanded ed. (Oxford: Oxford University Press, 2005), 24–86; Melvyn P. Leffler, A Preponderance of Power: National Security, the Truman Administration, and the Cold War (Stanford, CA: Stanford University Press, 1992), 10–14; George F. Kennan, “Contemporary Problems in Foreign Policy,” speech to the National War College, September 17, 1948, George F. Kennan Papers, Princeton University Seeley G. Mudd Manuscript Library, https://findingaids.princeton.edu/catalog/MC076_c03141; Stephen M. Walt, “The Case for Finite Containment: Analyzing U.S. Grand Strategy,” International Security 14, no. 1 (Summer, 1989): 5–49; Stephen Van Evera, “Why Europe Matters, Why the Third World Doesn’t: American Grand Strategy After the Cold War,” Journal of Strategic Studies 13, no. 2 (1990): 1–51.

²⁸ Andrew Scott Cooper, The Oil Kings: How the U.S., Iran, and Saudi Arabia Changed the Balance of Power in the Middle East (New York: Simon & Schuster, 2011); Office of the Historian, Department of State, “Address by President Carter on the State of the Union Before a Joint Session of Congress,” January 23, 1980, https://history.state.gov/historicaldocuments/frus1977-80v01/d138; Zbigniew Brzezinski, Brent Scowcroft and Richard Murphy, “Differentiated Containment,” Foreign Affairs 76, no. 3 (May/June 1997): 10–20.

²⁹ An early post-Cold War Defense Planning Guidance was leaked to the press and quickly retracted, although its broad outlines were visible throughout subsequent decades of American foreign policy. “Excerpts From Pentagon's Plan: 'Prevent the Re-Emergence of a New Rival',” The New York Times, March 8, 1992, https://www.nytimes.com/1992/03/08/world/excerpts-from-pentagon-s-plan-prevent-the-re-emergence-of-a-new-rival.html. Also see Michael Mastanduno, “Preserving the Unipolar Moment: Realist Theories and U.S. Grand Strategy after the Cold War,” International Security 21, no. 4 (Spring, 1997): 49–88.

³⁰ See, for example, The President of the United States, A National Security Strategy of Engagement and Enlargement (The White House: July 1994), https://history.defense.gov/Portals/70/Documents/nss/nss1994.pdf; The President of the United States, The National Security Strategy of the United States (The White House: September 2002), https://2009-2017.state.gov/documents/organization/63562.pdf.

³¹ Porter, The Global Village Myth, 1–17.

³² Kieran Webb, “The Continued Importance of Geographic Distance and Boulding’s Loss of Strength Gradient,” Comparative Strategy 26, no. 4 (Oct. 2007): 295–310.

³³ For an argument that recent American military defeats are largely explained by the distance from the U.S. at which wars have been fought, see M. Patrick Hulme and Erik Gartzke, “The Tyranny of Distance: Assessing and Explaining the Apparent Decline in U.S. Military Performance,” International Studies Quarterly 65, no. 2 (June 2021): 542–550.

³⁴ Barry R. Posen, Restraint: A New Foundation for U.S. Grand Strategy (Ithaca: Cornell University Press, 2014), 25.

³⁵ T.X. Hammes, “The Tactical Defense Becomes Dominant Again,” Joint Force Quarterly 103 (4th Quarter, 2021): 10–17. For an overview of offense-defense theory, see the essays collected in Michael E. Brown, et al., eds, Offense, Defense, and War (Cambridge, MA: MIT Press, 2004).

³⁶ Josh Holder, “Who’s Gaining Ground in Ukraine? This Year, No One,” New York Times, September 28, 2023, https://www.nytimes.com/interactive/2023/09/28/world/europe/russia-ukraine-war-map-front-line.html.

³⁷ Robert S. Ross, “The Geography of Peace: East Asia in the Twenty-First Century,” International Security 23, no. 4 (Spring, 1999): 81–118.

³⁸ Eugene Gholz, Benjamin Friedman, and Enea Gjoza, “Defensive Defense: A Better Way to Protect U.S. Allies in Asia,” Washington Quarterly 42, no. 4 (Winter 2020): 171–189.

³⁹ T.X. Hammes, “Offshore Control: A Proposed Strategy for an Unlikely Conflict,” Strategic Forum 278, National Defense University, June 2012, https://ndupress.ndu.edu/Portals/68/Documents/stratforum/SF-278.pdf.

⁴⁰ Christopher McCallion, “Grand Strategy: The Balance of Power,” Defense Priorities, April 16, 2024, https://www.defensepriorities.org/explainers/grand-strategy/the-balance-of-power.

⁴¹ Eugene Gholz and Daryl G. Press, “Protecting ‘the Prize’: Oil and the U.S. National Interest,” Security Studies 19, no. 3 (August, 2010), 453–485; International Energy Agency, “World Energy Balances: Overview,” accessed November 17, 2023, https://www.iea.org/reports/world-energy-balances-overview/world; U.S. Energy Information Administration, “Frequently Asked Questions: What is U.S. Electricity Generation by Energy Source?,” accessed November 17, 2023, https://www.eia.gov/tools/faqs/faq.php?id=427&t=3.

⁴² For some examples, see Carl Kaysen, “Is War Obsolete?: A Review Essay,” International Security 14, no. 4 (Spring, 1990): 42–64; Robert W. Tucker, The New Isolationism: Threat or Promise? (New York: Universe Books, 1972); Stephen Van Evera, “A Farewell to Geopolitics,” in To Lead the World: American Strategy after the Bush Doctrine, ed. by Melvyn P. Leffler and Jeffrey W. Legro (New York: Oxford University Press, 2008), 11–35.

⁴³ Jack S. Levy and William R. Thompson, “Balancing on Land and at Sea: Do States Ally against the Leading Global Power?” International Security 35, no. 1 (Summer 2010): 7–43. The distinction between continental and insular powers is made by Mearsheimer, The Tragedy of Great Power Politics, 126–128.

⁴⁴ Stephen M. Walt, Taming American Power: The Global Response to U.S. Primacy (New York: W.W. Norton and Co., 2005), 124.

⁴⁵ For reasons suggested by Layne, The Peace of Illusions, 182.

⁴⁶ Barry R. Posen, “Command of the Commons: The Military Foundation of U.S. Hegemony,” International Security 28, no. 1 (Summer, 2003): 5–46.

⁴⁷ Posen, Restraint, 135–144.

⁴⁸ Abraham Lincoln, “The Perpetuation of Our Political Institutions,” Address before the Young Men's Lyceum of Springfield, January 27, 1838, https://quod.lib.umich.edu/j/jala/2629860.0006.103/--perpetuation-of-our-political-institutions-address?rgn=main;view=fulltext.

⁴⁹ Quoted by Stephen M. Walt, “5 Things in the World to be Thankful for in 2023,” Foreign Policy, November 23, 2023, https://foreignpolicy.com/2023/11/23/thanksgiving-thankful-world-geopolitics-china-america-great-power-humanitarianism/.