"The threat of an encirclement of the United States by a European-Asiatic combination, which first emerged at the time of President Monroe, reappeared at the time of the First World War, and lay dormant in the British-Japanese Alliance, has again appeared, but on a scale undreamt of in former times." 
Nicholas J. Spykman, America's Strategy in World Politics  (1942)

The United States is in the midst of a strategic refocus from counterterrorism and rogue nation control, to so-called great power competition. While Russia, the Cold War counterpart, remains a concern, China has emerged as the primary near-peer threat. This is reawakening a key element that has long shaped U.S. foreign policy and strategic assessment — the major power of the Eurasian continent. But U.S. culture is split over the best way to deal with a Eurasian competitor, and domestic political and economic divisions will make it difficult for the United States to maintain a consistent strategy. 

The New Eurasia Challenge 

In his 1942 book, America's Strategy in World Politics: The United States and the Balance of Power, the U.S. social scientist Nicholas J. Spykmam made a very clear case of why an isolationist continentalist United States was not secure in the modern world. Spykman also identified a rimland, stretching around the periphery of Eurasia, where land meets sea, and where the maritime powers contend with the great continental power. It was Spykman's elucidation that helped shape the strategic thinking behind the later U.S. Cold War policy of containment, and the need for U.S. intervention around the Eurasian periphery. The Korean and Vietnam wars were both fought in the rimland, as were the U.S. relationships with Pakistan, Persia and Europe. Current U.S. overseas basing, and a very activist U.S. military, are all legacies of the internationalist concepts laid down by the likes of Spykman.

The United States now faces a new type of Eurasian competitor in China, one that is both continental and maritime. China's Belt and Road Initiative seeks to link the resources, markets and productive capacity of Mackinder's World Island (Asia, Europe and Africa), with Beijing at the center. China is also reaching out beyond Eurasia, across the Arctic, Pacific and Atlantic, to tap into the Americas. Should China prove successful, it would represent Spykman's encircling power, one that could exert influence and force across the Atlantic and Pacific frontiers, and perhaps even along the opening Arctic front. 

Though China is not poised to take over Eurasia and strangle U.S. trade along each coast any time soon, if at all, strategic thought looks to future potential capabilities, not current capacity or intent. And that raises again the core strategic dichotomy between continentalism and internationalism. While there is general agreement across the political aisle that China is a strategic competitor, if not the chief near-peer power challenger to the United States, there is little consensus on the strategy to deal with that challenge. 

Even inside the current administration of U.S. President Donald Trump, there are contradictory strategic policies. There is a drive to reduce the U.S. military footprint abroad, to withdraw troops, shrink overseas basing and, in some ways, try to pull back into fortress America. And at the same time, there is a drive to declare an ideological battle with China, to enhance U.S. forces abroad, particularly in the rimland around China, to keep the confrontation with China on and around the Eurasian landmass, and to disrupt China's economic and political expansion. 

The Struggle for Balance

Such a dichotomy is not unique to the Trump administration — U.S. policy is often pulled by the competing forces of continentalism and internationalism, and similar swings were seen during the Cold War. Nor is it merely the cognitive dissonance of the foreign policy elite in Washington. There is widespread general public support for withdrawing U.S. forces after nearly two decades of overseas conflict, as well as rising U.S. recognition of China as an opposing power to U.S. interests abroad. Partisan politics can play into this seemingly contradictory viewpoint, but it isn't the root cause. America's general prosperity and isolation strengthens the sense of continentalism, particularly when it faces economic hardship. But the undercurrent of American exceptionalism, whether couched in terms of democracy, morality or modern individual rights, reinforces the internationalist bent. 

The question facing the United States over the next decade or more is not just what to do about China, but how to do it. The United States remains a potent military and economic power, but it is also facing significant social and economic challenges that will reinforce the need to strengthen the homeland before seeking change abroad. The COVID-19 crisis, strong social divisions and extreme partisanship will compel the U.S. government to look inward, as well as U.S. citizens to urge more spending at home rather than on foreign military action.

At the same time, despite recent calls for reshaping supply chains and "decoupling" with China, the United States cannot simply withdraw into a shell and hope that things in the Eastern Hemisphere have no impact at home. Even in its most continentalist moments in the past, the United States has not been truly isolationist, nor has it been able to tease itself away from global commerce, both to absorb U.S. surplus (today in services more than manufactures), or to bring in critical raw materials. Even if the United States decides to take a more limited role abroad, it will not be immune to shifting geopolitical patterns that would impact resources and market access. As Mackinder noted and Spykman reiterated, the world is a closed system, and events in one place now ripple around the globe, whether we want them to or not. 

Both internationalism and continentalism have their costs and rewards, but it is hard to effectively straddle the line. An internationalist strategy requires active combined political, economic and military influence around the Eurasian periphery, ideally in close cooperation with partners and allies. Attempting to be only partially internationalist quickly sees the strategy lose focus, sees allies lose trust, and paves the way for the Eurasian competitor to exploit the attendant fractures. A purely continentalist strategy that seeks to strengthen the homeland and maintain trade through professed neutrality, but does little to intervene to shape developments in Eurasia, can last only a brief amount of time before the shifting global power balance begins to impinge on America's sense of security, triggering a return to an internationalist course.