The national conversation about America’s potential “decline,” however defined, tends to rely on an understanding in which power is conceptualized in simple metrics rather than holistic terms. Consider the preoccupation with when the absolute gross domestic product of China will overtake the United States, even though the overall size of an economy is only one measure of economic power. Instead of worrying about the relative weakening of specific metrics, the United States should focus on renewing the liberal international order—a system that has both contributed to and benefited from its leadership for almost seven decades, while at the same time facilitating significant gains in global peace and prosperity.
While the rise of other countries implies relative U.S. decline, that phenomenon can coexist with continued leadership in international affairs. This is arguably one of the chief insights of America’s postwar foreign policy. With Europe and Asia lying in ruins, the United States could have succumbed to short-sighted opportunism in pursuit of a unipolar world. Indeed, this was a temptation that some commentators would urge it to act upon following the Soviet Union’s dissolution half a century later. Instead, it undertook to resuscitate Europe and Asia, betting—correctly—that their revival would strengthen its leadership, not weaken it.
Consider just the period of 1950 to 2000: Gross world product (GWP) increased almost seven-fold, going from $5.3 trillion to $36.7 trillion (in 1990 international dollars), and GWP per capita increased almost three-fold, going from a little over $2,000 to just over $6,000. Global merchandise exports increased over 100-fold, going from $62 billion to almost $6.5 trillion (in current U.S. dollars). Battle deaths from state-based armed conflicts fell from almost 600,000 to less than 100,000. Average global life expectancy rose from 47 years to 65 years.
As of yet, there is no coherent alternative to the liberal international order that made all of this growth possible, nor is there a country or coalition that can readily replace the United States in underpinning it. Even so, Washington cannot be complacent if it seeks to sustain that system, let alone expand its constituency. China and emerging powers such as Brazil are bound to it because of strategic imperatives—including economic growth—not because of a deeper allegiance that proceeds from shared values. Were an alternative framework to emerge that could sustain global commerce as effectively, they would, appropriately, seek to withdraw from the current one—especially if they could shape the new one’s norms and arrangements.
But perhaps more significantly, economic weakness at home and military overextension abroad make it increasingly untenable for the United States to serve in its current capacity without greater assistance. Eric X. Li warns, perhaps hyperbolically in some observers’ eyes, that “[t]he attempt to play the dual role of ruler and participant has cost America dearly…The weight of free riders is crushing the one participant who would be ruler.”