The third phase of the early American expansion strategy was in essence an extension of the National Road via a series of settlement trails, by far the most important and famous of which was the Oregon Trail. While less of a formal construction than the National Road, the Oregon Trail opened up far larger territories. The trail was directly responsible for the initial settling of Kansas, Nebraska, Wyoming, Idaho and Oregon. A wealth of secondary trails branched off from the main artery — the Mormon, Bozeman, California and Denver trails — and extended the settlement efforts to Montana, Colorado, Utah, Nevada and California. The trails were all active from the early 1840s until the completion of the country's first transcontinental railway in 1869. That project's completion reduced East Coast-West Coast travel time from six months to eight days and slashed the cost by 90 percent (to about $1,100 in 2011 dollars). The river of settlers overnight turned into a flood, finally cementing American hegemony over its vast territories.



Collectively, the Louisiana Purchase, the National Road and the Oregon Trail facilitated the largest and fastest cultural expansion in human history. From beginning to end, the entire process required less than 70 years. However, it should be noted that the last part of this process — the securing of the West Coast — was not essential to American security. The Columbia River Valley and California's Central Valley are not critical American territories. Any independent entities based in either could not possibly generate a force capable of threatening the Greater Mississippi Basin. This hardly means that these territories are unattractive or a net loss to the United States — among other things, they grant the United States full access to the Pacific trading basin — only that control of them is not imperative to American security.

2. Eliminate All Land-Based Threats to the Greater Mississippi Basin

The first land threat to the young United States was in essence the second phase of the Revolutionary War — a rematch between the British Empire and the young United States in the War of 1812. That the British navy could outmatch anything the Americans could float was obvious, and the naval blockade was crushing to an economy dependent upon coastal traffic. Geopolitically, the most critical part of the war was the participation of semi-independent British Canada. It wasn't so much Canadian participation in any specific battle of the war (although Canadian troops did play a leading role in the sacking of Washington in August 1814) as it was that Canadian forces, unlike the British, did not have a supply line that stretched across the Atlantic. They were already in North America and, as such, constituted a direct physical threat to the existence of the United States.



Canada lacked many of the United States' natural advantages even before the Americans were able to acquire the Louisiana Territory. First and most obvious, Canada is far enough north that its climate is far harsher than that of the United States, with all of the negative complications one would expect for population, agriculture and infrastructure. What few rivers Canada has neither interconnect nor remain usable year round. While the Great Lakes do not typically freeze, some of the river connections between them do. Most of these river connections also have rapids and falls, greatly limiting their utility as a transport network. Canada has made them more usable via grand canal projects, but the country's low population and difficult climate greatly constrain its ability to generate capital locally. Every infrastructure project comes at a great opportunity cost, such a high cost that the St. Lawrence Seaway — a series of locks that link the St. Lawrence River to the Great Lakes and allow full ocean access — was not completed until 1959.



Canada is also greatly challenged by geography. The maritime provinces — particularly Newfoundland and Prince Edward Island — are disconnected from the Canadian landmass and unable to capitalize on what geographic blessings the rest of the country enjoys. They lack even the option of integrating south with the Americans and so are perennially poor and lightly populated compared to the rest of the country. Even in the modern day, what population centers Canada does have are geographically sequestered from one another by the Canadian Shield and the Rocky Mountains.



As time advanced, none of Canada's geographic weaknesses worked themselves out. Even the western provinces — British Columbia, Alberta, Saskatchewan and Manitoba — are linked to Canada's core by only a single transport corridor that snakes 1,500 kilometers through the emptiness of western and central Ontario north of Lake Superior. All four provinces have been forced by geography and necessity to be more economically integrated with their southern neighbors than with their fellow Canadian provinces.



Such challenges to unity and development went from being inconvenient and expensive to downright dangerous when the British ended their involvement in the War of 1812 in February 1815. The British were exhausted from the Napoleonic Wars in Europe and, with the French Empire having essentially imploded, were more interested in reshaping the European balance of power than re-engaging the Americans in distant North America. For their part, the Americans were mobilized, angry and — remembering vividly the Canadian/British sacking of Washington — mulling revenge. This left a geographically and culturally fractured Canada dreading a long-term, solitary confrontation with a hostile and strengthening local power. During the following decades, the Canadians had little choice but to downgrade their ties to the increasingly disinterested British Empire, adopt political neutrality vis-a-vis Washington, and begin formal economic integration with the United States. Any other choice would have put the Canadians on the path to another war with the Americans (this time likely without the British), and that war could have had only one outcome.



With its northern border secured, the Americans set about excising as much other extra-hemispheric influence from North America as possible. The Napoleonic Wars had not only absorbed British attention but had also shattered Spanish power (Napoleon actually succeeded in capturing the king of Spain early in the conflicts). Using a combination of illegal settlements, military pressure and diplomacy, the United States was able to gain control of east and west Florida from Madrid in 1819 in exchange for recognizing Spanish claims to what is now known as Texas (Tejas to the Spanish of the day).



This "recognition" was not even remotely serious. With Spain reeling from the Napoleonic Wars, Spanish control of its New World colonies was frayed at best. Most of Spain's holdings in the Western Hemisphere either had already established their independence when Florida was officially ceded, or — as in Mexico — were bitterly fighting for it. Mexico achieved its independence a mere two years after Spain ceded Florida, and the United States' efforts to secure its southwestern borders shifted to a blatant attempt to undermine and ultimately carve up the one remaining Western Hemispheric entity that could potentially challenge the United States: Mexico.



The Ohio and Upper Mississippi basins were hugely important assets, since they provided not only ample land for settlement but also sufficient grain production and easy transport. Since that transport allowed American merchants to easily access broader international markets, the United States quickly transformed itself from a poor coastal nation to a massively capital-rich commodities exporter. But these inner territories harbored a potentially fatal flaw: New Orleans. Should any nation but the United States control this single point, the entire maritime network that made North America such valuable territory would be held hostage to the whims of a foreign power. This is why the United States purchased New Orleans.



But even with the Louisiana Purchase, owning was not the same as securing, and all the gains of the Ohio and Louisiana settlement efforts required the permanent securing of New Orleans. Clearly, the biggest potential security threat to the United States was newly independent Mexico, the border with which was only 150 kilometers from New Orleans. In fact, New Orleans' security was even more precarious than such a small distance suggested.



Most of eastern Texas was forested plains and hills with ample water supplies — ideal territory for hosting and supporting a substantial military force. In contrast, southern Louisiana was swamp. Only the city of New Orleans itself could house forces, and they would need to be supplied from another location via ship. It did not require a particularly clever military strategy for one to envision a Mexican assault on the city.



The United States defused and removed this potential threat by encouraging the settlement of not just its own side of the border region but the other side as well, pushing until the legal border reflected the natural border — the barrens of the desert. Just as the American plan for dealing with Canada was shaped by Canada's geographic weakness, Washington's efforts to first shield against and ultimately take over parts of Mexico were shaped by Mexico's geographic shortcomings.



In the early 1800s Mexico, like the United States, was a very young country and much of its territory was similarly unsettled, but it simply could not expand as quickly as the United States for a variety of reasons. Obviously, the United States enjoyed a head start, having secured its independence in 1783 while Mexico became independent in 1821, but the deeper reasons are rooted in the geographic differences of the two states.



In the United States, the cheap transport system allowed early settlers to quickly obtain their own small tracts of land. It was an attractive option that helped fuel the early migration waves into the United States and then into the continent's interior. Growing ranks of landholders exported their agricultural output either back down the National Road to the East Coast or down the Ohio and Mississippi rivers and on to Europe. Small towns formed as wealth collected in the new territories, and in time the wealth accumulated to the point that portions of the United States had the capital necessary to industrialize. The interconnected nature of the Midwest ensured sufficient economies of scale to reinforce this process, and connections between the Midwest and the East Coast were sufficient to allow advances in one region to play off of and strengthen the other.



Mexico, in contrast, suffered from a complete lack of navigable rivers and had only a single good port (Veracruz). Additionally, what pieces of arable land it possessed were neither collected into a singular mass like the American interior nor situated at low elevations. The Mexico City region is arable only because it sits at a high elevation — at least 2,200 meters above sea level — lifting it out of the subtropical climate zone that predominates at that latitude.



This presented Mexico with a multitude of problems. First and most obviously, the lack of navigable waterways and the non-abundance of ports drastically reduced Mexico's ability to move goods and thereby generate its own capital. Second, the disassociated nature of Mexico's agricultural regions forced the construction of separate, non-integrated infrastructures for each individual sub-region, drastically raising the costs of even basic development. There were few economies of scale to be had, and advances in one region could not bolster another. Third, the highland nature of the Mexico City core required an even more expensive infrastructure, since everything had to be transported up the mountains from Veracruz. The engineering challenges and costs were so extreme and Mexico's ability to finance them so strained that the 410-kilometer railway linking Mexico City and Veracruz was not completed until 1873. (By that point, the United States had two intercontinental lines and roughly 60,000 kilometers of railways.)



The higher cost of development in Mexico resulted in a very different economic and social structure compared to the United States. Instead of small landholdings, Mexican agriculture was dominated by a small number of rich Spaniards (or their descendants) who could afford the high capital costs of creating plantations. So whereas American settlers were traditionally yeoman farmers who owned their own land, Mexican settlers were largely indentured laborers or de facto serfs in the employ of local oligarchs. The Mexican landowners had, in essence, created their own company towns and saw little benefit in pooling their efforts to industrialize. Doing so would have undermined their control of their economic and political fiefdoms. This social structure has survived to the modern day, with the bulk of Mexican political and economic power held by the same 300 families that dominated Mexico's early years, each with its local geographic power center.



For the United States, the attraction of owning one's own destiny made it the destination of choice for most European migrants. At the time that Mexico achieved independence it had 6.2 million people versus the U.S. population of 9.6 million. In just two generations — by 1870 — the American population had ballooned to 38.6 million while Mexico's was only 8.8 million. This U.S. population boom, combined with the United States' ability to industrialize organically, not only allowed it to develop economically but also enabled it to provide the goods for its own development.



The American effort against Mexico took place in two theaters. The first was Texas, and the primary means was settlement as enabled by the Austin family. Most Texas scholars begin the story of Texas with Stephen F. Austin, considered to be the dominant personality in Texas' formation. Stratfor starts earlier with Stephen's father, Moses Austin. In December 1796, Moses relocated from Virginia to then-Spanish Missouri — a region that would, within a decade, become part of the Louisiana Purchase — and began investing in mining operations. He swore fealty to the Spanish crown but obtained permission to assist with settling the region — something he did with American, not Spanish, citizens. Once Missouri became American territory, Moses shifted his attention south to the new border and used his contacts in the Spanish government to replicate his Missouri activities in Spanish Tejas.



After Moses' death in 1821, his son took over the family business of establishing American demographic and economic interests on the Mexican side of the border. Whether the Austins were American agents or simply profiteers is irrelevant; the end result was an early skewing of Tejas in the direction of the United States. Stephen's efforts commenced the same year as his father's death, which was the same year that Mexico's long war of independence against Spain ended. At that time, Spanish/Mexican Tejas was nearly devoid of settlers — Anglo or Hispanic — so the original 300 families that Stephen F. Austin helped settle in Tejas immediately dominated the territory's demography and economy. And from that point on the United States not so quietly encouraged immigration into Mexican Tejas.



Once Tejas' population identified more with the United States than it did with Mexico proper, the hard work was already done. The remaining question was how to formalize American control, no small matter. When hostilities broke out between Mexico City and these so-called "Texians," U.S. financial interests — most notably the U.S. regional reserve banks — bankrolled the Texas Revolution of 1835-1836.



It was in this war that one of the most important battles of the modern age was fought. After capturing the Alamo, Mexican dictator Gen. Antonio Lopez de Santa Anna marched north and then east with the intention of smashing the Texian forces in a series of engagements. With the Texians outnumbered by a factor of more than five to one, there was every indication that the Mexican forces would prevail over the Texian rebels. But with no small amount of luck the Texians managed not only to defeat the Mexican forces at the Battle of San Jacinto but also capture Santa Anna himself and force a treaty of secession upon the Mexican government. An independent Texas was born and the Texians became Texans.



However, had the battle gone the other way the Texian forces would not have simply been routed but crushed. It was obvious to the Mexicans that the Texians had been fighting with weapons made in the United States, purchased from the United States with money lent by the United States. Since there would have been no military force between the Mexican army and New Orleans, it would not have required a particularly ingenious plan for Mexican forces to capture New Orleans. It could well have been Mexico — not the United States — that controlled access to the North American core.



But Mexican supremacy over North America was not to be, and the United States continued consolidating. The next order of business was ensuring that Texas neither fell back under Mexican control nor was able to persist as an independent entity.



Texas was practically a still-born republic. The western half of Texas suffers from rocky soil and aridity, and its rivers are for the most part unnavigable. Like Mexico, its successful development would require a massive application of capital, and it attained its independence only by accruing a great deal of debt. That debt was owed primarily to the United States, which chose not to write off any upon conclusion of the war. Add in that independent Texas had but 40,000 people (compared to the U.S. population at the time of 14.7 million) and the future of the new country was — at best — bleak.



Texas immediately applied for statehood, but domestic (both Texan and American) political squabbles and a refusal of Washington to accept Texas' debt as an American federal responsibility prevented immediate annexation. Within a few short years, Texas' deteriorating financial position combined with a revenge-minded Mexico hard by its still-disputed border forced Texas to accede to the United States on Washington's terms in 1845. From that point the United States poured sufficient resources into its newest territory (ultimately exchanging approximately one-third of Texas' territory for the entirety of the former country's debt burden in 1850, giving Texas its contemporary shape) and set about enforcing the new U.S.-Mexico border.



Which brings us to the second part of the American strategy against Mexico. While the United States was busy supporting Texian/Texan autonomy, it was also undermining Spanish/Mexican control of the lands of what would become the American Southwest farther to the west. The key pillar of this strategy was another of the famous American trails: the Santa Fe.



Contrary to conventional wisdom, the Santa Fe Trail was formed not only before the New Mexico Territory became American, or even before Texas became an U.S. state, but before the territory become formally Mexican — the United States founded the trail when Santa Fe was still held by Spanish authority. The trail's purpose was twofold: first, to fill the region on the other side of the border with a sufficient number of Americans so that the region would identify with the United States rather than with Spain or Mexico and, second, to establish an economic dependency between the northern Mexican territories and the United States.



The United States' more favorable transport options and labor demography granted it the capital and skills it needed to industrialize at a time when Mexico was still battling Spain for its independence. The Santa Fe Trail started filling the region not only with American settlers but also with American industrial goods that Mexicans could not get elsewhere in the hemisphere.



Even if the race to dominate the lands of New Mexico and Arizona had been a fair one, the barrens of the Chihuahuan, Sonoran and Mojave deserts greatly hindered Mexico's ability to settle the region with its own citizens. Mexico quickly fell behind economically and demographically in the contest for its own northern territories. (Incidentally, the United States attempted a similar settlement policy in western Canada, but it was halted by the War of 1812.)



The two efforts — carving out Texas and demographically and economically dominating the Southwest — came to a head in the 1846-1848 Mexican-American War. In that war the Americans launched a series of diversionary attacks across the border region, drawing the bulk of Mexican forces into long, arduous marches across the Mexican deserts. Once Mexican forces were fully engaged far to the north of Mexico's core territories — and on the wrong side of the deserts — American forces made an amphibious landing and quickly captured Mexico's only port at Veracruz before marching on and capturing Mexico City, the country's capital. In the postwar settlement, the United States gained control of all the lands of northern Mexico that could sustain sizable populations and set the border with Mexico through the Chihuahuan Desert, as good of an international border as one can find in North America. This firmly eliminated Mexico as a military threat.

3. Control the Ocean Approaches to North America

With the United States having not simply secured its land borders but having ensured that its North American neighbors were geographically unable to challenge it, Washington's attention shifted to curtailing the next potential threat: an attack from the sea. Having been settled by the British and being economically integrated into their empire for more than a century, the Americans understood very well that sea power could be used to reach them from Europe or elsewhere, outmaneuver their land forces and attack at the whim of whoever controlled the ships.



But the Americans also understood that useful sea power had requirements. The Atlantic crossing was a long one that exhausted its crews and passengers. Troops could not simply sail straight across and be dropped off ready to fight. They required recuperation on land before being committed to a war. Such ships and their crews also required local resupply. Loading up with everything needed for both the trip across the Atlantic and a military campaign would leave no room on the ships for troops. As naval technology advanced, the ships themselves also required coal, which necessitated a constellation of coaling stations near any theaters of operation. Hence, a naval assault required forward bases that would experience traffic just as heavy as the spear tip of any invasion effort.



Ultimately, it was a Russian decision that spurred the Americans to action. In 1821 the Russians formalized their claim to the northwest shore of North America, complete with a declaration barring any ship from approaching within 100 miles of their coastline. The Russian claim extended as far south as the 51st parallel (the northern extreme of Vancouver Island). A particularly bold Russian effort even saw the founding of Fort Ross, less than 160 kilometers north of San Francisco Bay, in order to secure a (relatively) local supply of foodstuffs for Russia's American colonial effort.



In response to both the broader geopolitical need as well as the specific Russian challenge, the United States issued the Monroe Doctrine in 1823. It asserted that European powers would not be allowed to form new colonies in the Western Hemisphere and that, should a European power lose its grip on an existing New World colony, American power would be used to prevent their re-entrance. It was a policy of bluff, but it did lay the groundwork in both American and European minds that the Western Hemisphere was not European territory. With every year that the Americans' bluff was not called, the United States' position gained a little more credibility.



All the while the United States used diplomacy and its growing economic heft to expand. In 1867 the United States purchased the Alaska Territory from Russia, removing Moscow's weak influence from the hemisphere and securing the United States from any northwestern coastal approach from Asia. In 1898, after a generation of political manipulations that included indirectly sponsoring a coup, Washington signed a treaty of annexation with the Kingdom of Hawaii. This secured not only the most important supply depot in the entire Pacific but also the last patch of land on any sea invasion route from Asia to the U.S. West Coast.



The Atlantic proved far more problematic. There are not many patches of land in the Pacific, and most of them are in the extreme western reaches of the ocean, so securing a buffer there was relatively easy. On the Atlantic side, many European empires were firmly entrenched very close to American shores. The British held bases in maritime Canada and the Bahamas. Several European powers held Caribbean colonies, all of which engaged in massive trade with the Confederacy during the U.S. Civil War. The Spanish, while completely ejected from the mainland by the end of the 1820s, still held Cuba, Puerto Rico and the eastern half of Hispaniola (the modern-day Dominican Republic).



All were problematic to the growing United States, but it was Cuba that was the most vexing issue. Just as the city of New Orleans is critical because it is the lynchpin of the entire Mississippi watershed, Cuba, too, is critical because it oversees New Orleans' access to the wider world from its perch on the Yucatan Channel and Florida Straits. No native Cuban power is strong enough to threaten the United States directly, but like Canada, Cuba could serve as a launching point for an extra-hemispheric power. At Spain's height of power in the New World it controlled Florida, the Yucatan and Cuba — precisely the pieces of territory necessary to neutralize New Orleans. By the end of the 19th century, those holdings had been whittled down to Cuba alone, and by that time the once-hegemonic Spain had been crushed in a series of European wars, reducing it to a second-rate regional power largely limited to southwestern Europe. It did not take long for Washington to address the Cuba question.



In 1898, the United States launched its first-ever overseas expeditionary war, complete with amphibious assaults, long supply lines and naval support for which American warfighting would in time become famous. In a war that was as globe-spanning as it was brief, the United States captured all of Spain's overseas island territories — including Cuba. Many European powers retained bases in the Western Hemisphere that could threaten the U.S. mainland, but with Cuba firmly in American hands, they could not easily assault New Orleans, the only spot that could truly threaten America's position. Cuba remained a de facto American territory until the Cuban Revolution of 1959. At that point, Cuba again became a launching point for an extra-hemispheric power, this time the Soviet Union. That the United States risked nuclear war over Cuba is a testament to how seriously Washington views Cuba. In the post-Cold War era Cuba lacks a powerful external sponsor and so, like Canada, is not viewed as a security risk.



After the Spanish-American war, the Americans opportunistically acquired territories when circumstances allowed. By far the most relevant of these annexations were the results of the Lend-Lease program in the lead-up to World War II. The United Kingdom and its empire had long been seen as the greatest threat to American security. In addition to two formal American-British wars, the United States had fought dozens of skirmishes with its former colonial master over the years. It was British sea power that had nearly destroyed the United States in its early years, and it remained British sea power that could both constrain American economic growth and ultimately challenge the U.S. position in North America.



The opening years of World War II ended this potential threat. Beset by a European continent fully under the control of Nazi Germany, London had been forced to concentrate all of its naval assets on maintaining a Continental blockade. German submarine warfare threatened both the strength of that blockade and the ability of London to maintain its own maritime supply lines. Simply put, the British needed more ships. The Americans were willing to provide them — 50 mothballed destroyers to be exact — for a price. That price was almost all British naval bases in the Western Hemisphere. The only possessions that boasted good natural ports that the British retained after the deal were in Nova Scotia and the Bahamas.



The remaining naval approaches in the aftermath of Lend-Lease were the Azores (a Portuguese possession) and Iceland. The first American operations upon entering World War II were the occupations of both territories. In the post-war settlement, not only was Iceland formally included in NATO but its defense responsibilities were entirely subordinated to the U.S. Defense Department.

4. Control the World's Oceans

The two world wars of the early 20th century constituted a watershed in human history for a number of reasons. For the United States the wars' effects can be summed up with this simple statement: They cleared away the competition.



Global history from 1500 to 1945 is a lengthy treatise of increasing contact and conflict among a series of great regional powers. Some of these powers achieved supra-regional empires, with the Spanish, French and English being the most obvious. Several regional powers — Austria, Germany, Ottoman Turkey and Japan — also succeeded in extending their writ over huge tracts of territory during parts of this period. And several secondary powers — the Netherlands, Poland, China and Portugal — had periods of relative strength. Yet the two world wars massively devastated all of these powers. No battles were fought in the mainland United States. Not a single American factory was ever bombed. Alone among the world's powers in 1945, the United States was not only functional but thriving.



The United States immediately set to work consolidating its newfound power, creating a global architecture to entrench its position. The first stage of this — naval domination — was achieved quickly and easily. The U.S. Navy at the beginning of World War II was already a respectable institution, but after three years fighting across two oceans it had achieved both global reach and massive competency. But that is only part of the story. Equally important was the fact that, as of August 1945, with the notable exception of the British Royal Navy, every other navy in the world had been destroyed. As impressive as the United States' absolute gains in naval power had been, its relative gains were grander still. There simply was no competition. Always a maritime merchant power, the United States could now marry its economic advantages to absolute dominance of the seas and all global trade routes. And it really didn't need to build a single additional ship to do so (although it did anyway).



Over the next few years the United States' undisputed naval supremacy allowed the Americans to impose a series of changes on the international system.

The formation of NATO in 1949 placed all of the world's surviving naval assets under American strategic direction.

The inclusion of the United Kingdom, Italy, Iceland and Norway in NATO granted the United States the basing rights it needed to utterly dominate the North Atlantic and the Mediterranean — the two bodies of water that would be required for any theoretical European resurgence. The one meaningful European attempt to challenge the new reality — the Anglo-French Sinai campaign of 1956 — cemented the downfall of the European navies. Both London and Paris discovered that they now lacked the power to hold naval policies independent of Washington.

The seizure of Japan's Pacific empire granted the Americans basing access in the Pacific, sufficient to allow complete American naval dominance of the north and central portions of that ocean.

A formal alliance with Australia and New Zealand extended American naval hegemony to the southern Pacific in 1951.

A 1952 security treaty placed a rehabilitated Japan — and its navy — firmly under the American security umbrella.

Shorn of both independent economic vitality at home and strong independent naval presences beyond their home waters, all of the European empires quickly collapsed. Within a few decades of World War II's end, nearly every piece of the once globe-spanning European empires had achieved independence.



There is another secret to American success — both in controlling the oceans and taking advantage of European failures — that lies in an often-misunderstood economic structure called Bretton Woods. Even before World War II ended, the United States had leveraged its position as the largest economy and military to convince all of the Western allies — most of whose governments were in exile at the time — to sign onto the Bretton Woods accords. The states committed to the formation of the International Monetary Fund and World Bank to assist with the expected post-War reconstruction. Considering the general destitution of Western Europe at the time, this, in essence, was a U.S. commitment to finance if not outright fund that reconstruction. Because of that, the U.S. dollar was the obvious and only choice to serve as the global currency.



But Bretton Woods was about more than currency regimes and international institutions; its deeper purpose lay in two other features that are often overlooked. The United States would open its markets to participating states' exports while not requiring reciprocal access for its own. In exchange, participating states would grant the United States deference in the crafting of security policy. NATO quickly emerged as the organization through which this policy was pursued.



From the point of view of the non-American founders of Bretton Woods, this was an excellent deal. Self-funded reconstruction was out of the question. The bombing campaigns required to defeat the Nazis leveled most of Western Europe's infrastructure and industrial capacity. Even in those few parts of the United Kingdom that emerged unscathed, the state labored under a debt that would require decades of economic growth to recover from.



It was not so much that access to the American market would help regenerate Europe's fortunes as it was that the American market was the only market at war's end. And since all exports from Bretton-Woods states (which the exception of some Canadian exports) to the United States had to travel by water, and since the U.S. Navy was the only institution that could guarantee the safety of those exports, adopting security policies unfriendly to Washington was simply seen as a nonstarter. By the mid-1950s, Bretton Woods had been expanded to the defeated Axis powers as well as South Korea and Taiwan. It soon became the basis of the global trading network, first being incorporated into the General Agreement on Tariffs and Trade and in time being transformed into the World Trade Organization. With a single policy, the Americans not only had fused their economic and military policies into a single robust system but also had firmly established that American dominance of the seas and the global economic system would be in the interest of all major economies with the exception of the Soviet Union.

5. Prevent any Potential Challengers from Rising

From a functional point of view the United States controls North America because it holds nearly all of the pieces that are worth holding. With the possible exception of Cuba or some select sections of southern Canada, the rest of the landmass is more trouble than it is worth. Additionally, the security relationship it has developed with Canada and Mexico means that neither poses an existential threat to American dominance. Any threat to the United States would have to come from beyond North America. And the only type of country that could possibly dislodge the United States would be another state whose power is also continental in scope.



As of 2011, there are no such states in the international system. Neither are there any such powers whose rise is imminent. Most of the world is simply too geographically hostile to integration to pose significant threats. The presence of jungles, deserts and mountains and the lack of navigable rivers in Africa does more than make Africa capital poor; it also absolutely prevents unification, thus eliminating Africa as a potential seedbed for a mega-state. As for Australia, most of it is not habitable. It is essentially eight loosely connected cities spread around the edges of a largely arid landmass. Any claims to Australia being a "continental" power would be literal, not functional.



In fact, there are only two portions of the planet (outside of North America) that could possibly generate a rival to the United States. One is South America. South America is mostly hollow, with the people living on the coasts and the center dominated by rainforests and mountains. However, the Southern Cone region has the world's only other naturally interconnected and navigable waterway system overlaying arable land, the building blocks of a major power. But that territory — the Rio de la Plata region — is considerably smaller than the North American core and it is also split among four sovereign states. And the largest of those four — Brazil — has a fundamentally different culture and language than the others, impeding unification.



State-to-state competition is hardwired into the Rio de la Plata region, making a challenge to the United States impossible until there is political consolidation, and that will require not simply Brazil's ascendency but also its de facto absorption of Paraguay, Uruguay and Argentina into a single Brazilian superstate. Considering how much more powerful Brazil is than the other three combined, that consolidation — and the challenge likely to arise from it — may well be inevitable but it is certainly not imminent. Countries the size of Argentina do not simply disappear easily or quickly. So while a South American challenge may be rising, it is extremely unlikely to occur within a generation.



The other part of the world that could produce a rival to the United States is Eurasia. Eurasia is a region of extremely varied geography, and it is the most likely birthplace of an American competitor that would be continental in scope. Geography, however, makes it extremely difficult for such a power (or a coalition of such powers) to arise. In fact, the southern sub-regions of Eurasia cannot contribute to such formation. The Ganges River Basin is the most agriculturally productive in the world, but the Ganges is not navigable. The combination of fertile lands and non-navigable waterways makes the region crushingly overpopulated and poor.



Additionally, the mountains and jungles of South and Southeast Asia are quite literally the world's most difficult terrain. The countries in these sub-regions cannot expand beyond their mountain boundaries and have yet to prove that they can unify the resources within their regions (with the India-Pakistan rivalry being the most obvious example of sub-regional non-unity). The lands of the Middle East are mostly desert with the bulk of the population living either near the coasts — and thus very vulnerable to American naval power — or in river valleys that are neither productive enough to support an agenda of power projection nor accessible enough to encourage integration into a larger whole. Only the Fertile Crescent has reliable agriculture, but that agriculture is only possible with capital- and labor-intensive irrigation. The region's rivers are not navigable, and its lands are split among three different states adhering to three different religions (and that excludes fractious Lebanon).



That leaves only the lands of northern Eurasia — Europe, the former Soviet Union and China — as candidates for an anti-American coalition of substance. Northern Eurasia holds even more arable land than North America, but it is split among three regions: the North European Plain, the Eurasian steppe and the Yellow River basin. Although the developed lands of the North European Plain and the Eurasian steppe are adjacent, they have no navigable waterways connecting them, and even within the North European Plain none of its rivers naturally interconnects.



There is, however, the potential for unity. The Europeans and Russians have long engaged in canal-building to achieve greater economic linkages (although Russian canals linking the Volga to the sea all freeze in the winter). And aside from the tyranny of distance, there are very few geographic barriers separating the North European Plain from the Eurasian steppe from the Yellow River region, allowing one — theoretically — to travel from Bordeaux to the Yellow Sea unimpeded.