A century ago, an influenza pandemic killed more people than died in World War I. Today, the Covid-19 pandemic has killed more Americans than died in all US wars since 1945. A big difference, however, is that science didn’t have a vaccine for the influenza virus back then, but now several companies and countries have created vaccines for Covid-19.

A number of wealthy democracies, including the United States and the United Kingdom, have vaccinated over half their adult populations and seen a dramatic reduction in the number of new cases and deaths. Other places, such as India, Brazil and parts of Africa, have low vaccination rates and high rates of new cases and deaths. The Economist estimates ^[1] that the pandemic’s true global death toll may be something like 10 million people, or more than three times the official number reported by national authorities.

Given these grim statistics, should leaders of wealthy countries export vaccines and help vaccinate foreigners before they finish the job at home? When President Donald Trump proclaimed ‘America first’, he was being consistent with democratic theory, according to which leaders are entrusted with defending and advancing the interests of the people who elected them. But as I argue in my book Do morals matter? the key question is how leaders define the national interest. There’s a major moral difference between a myopic transactional definition, like that of Trump, and a broader, far-sighted definition.

Consider President Harry Truman’s espousal of the Marshall Plan after World War II. Rather than narrowly insisting that America’s European allies repay their war loans, as the US had demanded after World War I, Truman dedicated more than 2% of America’s GDP to aiding Europe’s economic recovery. The process allowed Europeans to share in planning the continent’s reconstruction and produced a result that was good for them, but that also served America’s national interest in preventing communist control of Western Europe.

There are four major reasons why a Marshall Plan–like effort to vaccinate people in poor countries is in the US national interest. First, it is in Americans’ medical interest. Viruses don’t care about the nationality of the humans they kill. They simply seek a host to allow them to reproduce, and large populations of unvaccinated humans allow them to mutate and evolve new variants that can evade the protections our vaccines produce. Given modern travel, it’s only a matter of time before variants cross national borders. If a new variant arose that was capable of bypassing our best vaccines, we would have to develop a booster targeted at the new variant and vaccinate again, which could lead to more fatalities and more strain on the US medical system, as well as further lockdowns and economic damage.

Our values provide the second reason that a vaccine Marshall Plan is in America’s national interest. Some foreign policy experts contrast values with interests, but that is a false dichotomy. Our values are among our most important interests, because they tell us who we are as a people. Like most people, Americans care more about their co-nationals than about foreigners, but that doesn’t mean they’re indifferent to the suffering of others. Few would ignore a cry for help from a drowning person because she calls out in a foreign language. And while leaders are constrained by public opinion in a democracy, they often have considerable leeway to shape policy—and considerable resources to influence public sentiment.

A third national interest, related to the second, is soft power—the ability to influence others through attraction rather than coercion or payment. American values can be a source of soft power when others see our policies as benign and legitimate.

Most foreign policies combine hard and soft power. The Marshall Plan, for example, relied on hard economic resources and payments, but it also created a reputation for benignity and far-sightedness that attracted Europeans. As the Norwegian political scientist Geir Lundestad has argued ^[2], the American role in post-war Europe may have resembled an empire, but it was ‘an empire by invitation’. A policy of helping poor countries by providing vaccines, as well as aiding the development of their own healthcare systems’ capacities, would increase US soft power.

Finally, there is geopolitical competition. China quickly recognised that its soft power suffered from the origin story of Covid-19 in Wuhan. Not only was there a lack of clarity about how the virus originated, but in the early stages of the crisis, Chinese censorship and denial made the crisis worse than necessary before its authoritarian lockdown proved successful. Since then, China has assiduously pursued Covid-19 diplomacy in many parts of the world.

By donating medical equipment and vaccines to other countries, China has been working to change the international narrative from one of fault to one of attraction. The Biden administration has been playing catch-up, announcing ^[3] that it will release 60 million doses of the AstraZeneca vaccine, as well as 20 million additional doses of the Pfizer, Moderna and Johnson & Johnson vaccines. In addition, the administration has pledged US$4 billion in funding for the World Health Organization’s COVAX facility to help poor countries purchase vaccines and has supported a temporary waiver of intellectual property to help poor countries develop capacity.

In short, for four good reasons consistent with America’s history, values and self-interest, the US should lead a group of rich countries in a plan to vaccinate the rest of the world now, even before the job is finished at home.