Hours after his inauguration on January 20, President Donald Trump signed an executive order beginning America’s withdrawal from the World Health Organization, known as WHO.

The international agency, part of the United Nations, was founded in 1948 and includes 194 countries working together to fight the world’s toughest public health problems. It is the cornerstone of global health efforts, with a multinational staff fighting both communicable diseases—like COVID-19, Zika, and HIV—and chronic conditions, such as heart disease, diabetes, and cancer.

WHO also works to fight malnutrition, deliver vaccines, and provide assistance and technical guidance to people in poor and battle-scarred regions of the world. Its biennial budget is $6.8 billion. The U.S. is among the largest donors.

Over the years, WHO has worked to eradicate smallpox, reduce worldwide polio cases by 99%, and greatly reduce the prevalence of malaria and trachoma, the world’s leading cause of blindness.

According to the Kaiser Family Foundation, WHO has also played a key role in other landmark health achievements, including the Alma-Ata Declaration on primary health care (1978), the Framework Convention on Tobacco Control (adopted in 2003), and the 2005 revision of the International Health Regulations, an international agreement that outlines roles and responsibilities in preparing for and responding to international health emergencies.

Trump’s executive order is his second attempt to pull the U.S. out of the agency. His earlier plan, introduced during his first term, was reversed by former President Joseph Biden.

Trump has long criticized WHO for what he has called “failure to adopt urgently needed reforms.” He has also complained that the U.S. financial contribution to the international organization is “onerous.”

Trump’s announcement was not a surprise, but it was jarring for the public health community. Withdrawal from WHO could isolate the United States health system, including federal agencies such as the National Institutes of Health, the Food and Drug Administration, and the Centers for Disease Control and Prevention.

We interviewed Stefano M. Bertozzi, former dean and current professor of health policy and management at UC Berkeley School of Public Health, about what risks withdrawing from WHO may pose.

Bertozzi has worked previously with the Bill & Melinda Gates Foundation, the Mexican National Institute of Public Health, UNAIDS, the World Bank, and the Government of Zaire. He is also the former director a.i. of the WHO Global Programme on AIDS, the precursor to UNAIDS.

UCBPH: What was your reaction to President Trump’s executive order starting a withdrawal from the World Health Organization, and calling American WHO staff home?

Bertozzi: As Dean Michael C. Lu has said, it’s really important that we remember that we have to distinguish between rhetoric and action. I don’t think any of us knows whether this is bluster as a negotiating position somehow, or whether this is actually something that will be done. I do think we have to take it very seriously, because President Trump did it last time.

If it’s true—if it happens—it is tragic for the U.S., and of course the rest of the world as well. I would have thought that we learned very well from the COVID-19 pandemic that there is no way that you can isolate yourself from the world and be safe from the many health threats that don’t respect borders—infectious diseases being just one of those. Anything we do that diminishes our ability to not only collaborate, but collaborate efficiently with countries all over the world—regardless of whether we agree with them politically—to stop global health threats, is really important.

Why is WHO so critical for public health?

One of the things that WHO does is provide a neutral forum where we can have discussions about health issues with every country in the world, whether or not we currently have diplomatic relations with them.

We can work together to stop threats from becoming global pandemics or otherwise threatening the world. That’s everything from recognizing a new spillover from an animal to a person that is starting an epidemic of a brand-new disease; to working together on laboratory safety to prevent leaks from laboratories; to working together to track the emergence of antimicrobial resistance for existing diseases for which we have effective antibiotics, but for which we may lose that effectiveness as antimicrobial resistance spreads. Fires cross borders and so does smoke—thinking of a very recent example. There are just so many issues that cross borders.

You view WHO as unique among multilateral agencies and treaties, correct?

It is extraordinary that the United States would pull out of WHO without identifying an alternative! What would the U.S. do, create its own bilateral health agency that collaborates with every country in the world? Frankly, it’s quite inconceivable.

It’s one thing when the U.S. pulled out of UNESCO [at the end of 2018], because we don’t have the same level of interdependence in global education that we do in global health. But this would be like saying we’re going to pull out of the World Trade Organization and we will stop respecting each other’s patent rights. Or, pull out of IATA and say that we no longer want to participate in setting global standards for international air travel. In all of those cases where we are interdependent—pulling out damages everyone, but it damages us the most. Right now we have the most say about what happens at WHO—how could we be better off when that is no longer the case?

Let’s talk about COVID-19. Critics of WHO have complained about the length of time that it took the agency to acknowledge that COVID-19 was airborne. Is that a valid criticism? After all, it was a big mistake.

It is a valid criticism. It was a big mistake that the U.S. also made. It was very unfortunate. I was upset at the time because we had pretty strong evidence of aerosolized transmission on the cruise ship Diamond Princess—and that was very early on. There was convincing data from China and Taiwan early on. So, yes, it did take too long.

But you don’t pull out of an organization because it makes a mistake. What you do is figure out why the mistake was made and try to improve the organization so that it is better prepared for next time.

I mean, the idea that we would pull out of WHO because it was too slow to recognize airborne transmission is crazy. What we need to do is work more closely with WHO to make sure that that doesn’t happen next time. Both the CDC and WHO need to get better at figuring out more quickly what the routes of transmission are for a new pathogen.

What will happen if the U.S. does actually withdraw from WHO?

What will probably happen is that even if the U.S. pulls out of WHO, there will be lots of arrangements for back channel communications that will continue, with the U.S. participating in key forums. And it might just mean that it’s a cosmetic withdrawal rather than a real withdrawal. But that may be the optimistic side of me. The pessimistic side of me says that it’ll take a disaster to bring the U.S. back into the fold.

I hope that that isn’t the case. I hope we don’t have to see something horrible happen for the U.S. to realize that being disconnected from WHO is not in its own interest, to say nothing about any interest in other countries in the world.

There is growing concern now about bird flu. Is that something WHO would have a role in tracking?

Yes, and it certainly concerns me. Bird flu is already here. We don’t know if in the future, bird flu will mutate enough so that it becomes highly transmissible from person to person.

Right now it is not, but that could change as it becomes better adapted to infecting humans. That’s exactly the kind of thing we want to be monitoring globally, and we want to collaborate with all other countries, not just the ones that we’re currently friends with.

What role did WHO play in the AIDS crisis?

During the HIV pandemic, WHO was really the only support to countries in Africa that were having these explosive epidemics. I mean, there was a small U.S. presence in the Congo—what was then Zaire—and later a presence in in Côte d’Ivoire, but every single African country stood up a national AIDS program and that only happened as quickly as it did because of very strong support from WHO staff who were in each country to help get those programs off the ground.

The WHO response was absolutely critical, and that was led by a guy named Jonathan Mann, an American epidemiologist.

What will happen to WHO without the U.S. contribution?

Losing the U.S. support would be a major blow to WHO. The U.S. is the largest contributor–about 20% of the budget–and it would require many other countries stepping up to fill that hole in the budget. And I hope that other countries would do that, because much of the work WHO does is critically important. You might think from listening to the news that supporting WHO is very costly but that is not true. It is responsible for supporting health efforts around the world and yet its annual budget is about half that of UCSF. Rather than cutting back on the U.S. contribution, the U.S. should be helping more to strengthen WHO’s capacity across many areas, including pandemic prevention, preparedness and response!