This summer, the journal Nature Food published a study which is, in many ways, a microcosm of a key force shaping the future of global health: the US-China relationship. Notably, the study did not concern COVID-19. It was about soybeans. The study found that China’s retaliatory tariffs on US agriculture could “cause unintended increases in nitrogen and phosphorus pollution and blue water extraction in the United States as farmers shift from soybeans to more pollution-causing crops.” The study also looked at the potential global ripple effects of the trade dispute, suggesting that, if China’s soybean demands were diverted to Brazil, meeting them “may add additional pressures on phosphorus pollution and deforestation.” Given the extent to which our health depends on the condition of the natural world, these environmental consequences pose, in themselves, a threat to public health. More broadly, however, the force underlying them—simmering conflict between global superpowers—reflects an even deeper challenge to health in both the near- and long-term.

In many ways, these tensions are part of a larger story—that of globalization. Public health has long been engaged with this story, as globalization has increasingly helped shape the macrosocial determinants of health. As countries become more interconnected, their relations with each other have ever-greater influence on the determinants of health, both within and without their borders. Rising tensions between the US and China—fueled by a range of economic, cultural, and historical forces—have long been part of the conversation about globalization. But they have only recently factored into the conversation about health in a significant way. The emergence and spread of the pandemic are inseparable from the geopolitical concerns of the moment. There is an ongoing debate about the origins of the virus—whether it leaked from a lab in China or was zoonotic in origin. Tensions between the US and China are a key reason why this debate remains unresolved. From the start of the pandemic, the Chinese government has been reluctant to share information about the virus, and the hostile posture of the superpowers has helped maintain this status quo. This has had consequences for our ability to address the pandemic as it unfolds, and to prevent future contagions. It also has implications for how we think about globalization and health more broadly, in a “shrinking” world. Great power conflict reminds us that health does not occur in a vacuum, that it is shaped by global forces which are now coming to the fore in the actions of great powers.

As the Nature Food study suggests, a resurgence of great power conflict has implications for health which extend far beyond the pandemic, intersecting with the full range of socioeconomic conditions that shape health. These include the economy, climate change, political shifts, and issues of war and peace—including the ever-present threat of nuclear war. In addition, US-China tensions also reflect the national divisions we have seen between and within many countries. From conflicts between Russia and its neighbors, to tensions between the UK and the European Union, to left-right divides here in the US, conflict has come to define our era to an extent which would likely have surprised those envisioning this century 30 years ago, through the lens of post-Cold War optimism. These conflicts all inform the challenges of our time. However, great power conflict is something relatively unique in the present moment, in these years after the Cold War, and is worth examining as a key challenge in itself, one with many implications for health. In doing so, I should note that these thoughts are not meant to minimize the challenges posed by strained relations between other countries; these are indeed worth serious consideration. However, tensions between superpowers, with an explicit focus on the US and China, are a distinct issue by orders of magnitude, and are worth special consideration, to help us better understand what the dynamics of this issue mean for health.  

In the post-Cold War era, it can be easy to forget that great power conflict was once far more the norm than it is today. In Europe alone, the history of the last few centuries is, in large part, the history of great power conflict, with Great Britain, Russia, Austria, France, and Prussia/Germany all playing key roles, their relative power rising and falling as these conflicts unfolded. These conflicts have all helped define the socioeconomic context of their respective ages, which have, in turn, shaped health. In more recent years, conflicts have been smaller in scale, often taking place within states, between smaller countries, or with superpowers engaging in conflict with smaller states, as we saw in Iraq and Afghanistan. It must also be said that a key difference between the great power conflicts of the past and of the current moment is the reality of nuclear weapons. These weapons, perhaps paradoxically, threaten the planet with annihilation while also helping minimize the chance of direct superpower conflict, by raising the costs of such a conflict to a level no one is willing to pay. This can also serve to prolong simmering conflict, as during the Cold War, by allowing tensions to unfold without leading to the potentially decisive denouement of full battlefield clash between superpowers, of the sort seen throughout the history of European wars.

Great power conflict in the 21st century is both a return to an older status quo and a new, historically unique challenge with its own set of novel complications and risks, with implications for health. What, then, are some of the key challenges US-China tension poses for health in the near- and long-term?

Setting aside the obvious risk of open war, the most existential risk posed by resurgent superpower conflict is likely its cost to the environment—specifically, its intersection with climate change. Making meaningful progress on climate change will be difficult, if not impossible, if the US and China cannot engage constructively on this issue. China is the world’s largest emitter of greenhouse gasses, followed by the US. Tension between the two countries complicates our efforts to solve this most urgent of problems, raising the possibility that even if this tension does not break out into war, it could still have dire consequences for the planet. At the same time, the environmental implications of everything from trade policy to the urbanization and industrial development of the two countries has ramifications for health. Leveraging these factors towards a healthier world will take a willingness to work together, sharing knowledge and resources, towards the global common good.

Graphic from: Report: China emissions exceed all developed nations combined. BBC News Accessed September 7, 2021.

Second, great power competition poses challenges to the international institutions tasked with supporting global health. Global bodies like the United Nations, the World Health Organization, and the World Trade Organization help establish mutually beneficial norms of conduct for countries to abide by, and help nations collaborate towards the common good. When these bodies become arenas for zero-sum competition, or their functions are abused or corrupted by states seeking to dominate and bully, they cannot effectively support a better, healthier world. Shoring up the integrity of these institutions means working within them to ensure the ambitions of great powers do not undermine the rules-based international order that is core to supporting health.

Third, great power competition can make us want to retreat behind our borders, to emphasize geographic and cultural divides, and to turn away from the world’s fundamental interconnectedness. COVID-19 was a reminder that disease knows no borders. A health challenge in China can become a problem for the whole world in a matter of months. But it does not take a pandemic to show us how decades of globalization have created a world in which one country—particularly a superpower—can have an outsized influence on global health through its export of goods and culture. The US, for example, has shaped the global diet, arguably for the worse, by contributing to the spread of fast food to seemingly all corners of the earth. China, for its part, has been a key source of the fentanyl coming into the US, fueling the opioid crisis. And the opening of Chinese markets to US companies has been inextricably linked to issues of free speechdata security, and corporate attitudes towards the Chinese government’s stance on human rights—all of which have implications for the future of a liberal order that supports human flourishing and health. This interconnectedness, and its intersection with health, is inseparable from the context of great power competition. We cannot fully reckon with this if we retrench behind our borders instead of pursuing an optimistic, forward-looking vision of a global future.

Fourth, it is important to note that less well-resourced countries will likely suffer most from the consequences of great power conflict. This is perhaps best captured by the effects of climate change, which disproportionately harm low-resource countries in vulnerable parts of the world. It is also the case that, in past conflicts, the wellbeing of smaller, less influential states was often overlooked or undermined by the self-interested maneuvering of great powers. From the wars and economic exploitation faced by Latin American countries as a consequence of actions of the Cold War superpowers, to colonial exploitation across the world in earlier eras, it is frequently the vulnerable who pay the biggest price for great power conflict.       

I raise these challenges mindful that there is no easy solution to them. The state of the US-China relationship is still very much in flux, its contours yet to be fully defined. The hunt for the origins of COVID-19 both reflects this ongoing evolution and has the potential to shape it. However, in the midst of unknowns, and facing an uncertain future, it strikes me that two core principles still apply, principles which have already done much to guide us towards a healthier world.

First, it is necessary, always, to reject xenophobia and hate, and to draw a distinction between the actions of a government and the people of a country. Such a distinction is necessary to ensure political disagreements do not devolve into attitudes of hate. They also help ensure that legitimate criticisms of a government’s policies remain possible, without being dismissed as hate when they may in fact be substantive and necessary. This would have helped at the start of the pandemic, for example, when legitimate, well-founded concerns over racism and anti-Asian hate were often conflated with concerns over the actions of both the Chinese and American governments, to say nothing of the conversation about the origins of the virus. We should be able to have frank discussions about these issues while being able to discern between concern over a country’s actions and racism against its people.

Finally, it is necessary to pursue the goal of better health for all as a unifying force, a universal aspiration which crosses national boundaries. The task of building a healthier world, post-COVID is a global challenge. No country is in a position to opt out of it, and this includes superpowers. It does not matter how wealthy or powerful a country is: our shared vulnerability to disease is something that links us all. The task of addressing it reflects a key opportunity for countries to come together, to mitigate tension, and to work towards a better world for everyone.


  • Sandro Galea is Dean and Robert A. Knox Professor at the Boston University School of Public Health. He has been named an "epidemiology innovator" by Time and one of the "World's Most Influential Scientific Minds" by Thomson Reuters. A native of Malta, he has served as a field physician for Doctors Without Borders and held academic positions at Columbia University, University of Michigan, and the New York Academy of Medicine. His new book, The Contagion Next Time, was published in fall 2021, and is available to order here:

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