Originally published 2021-01-22.
On his first day in office, 20 January 2021, President Joe Biden stopped the United States from leaving the World Health Organization. The country had never actually left: Donald Trump had filed a one-year withdrawal notice in July 2020, and Biden retracted it before it could take effect. The reversal held for four years. Trump restarted the exit on 20 January 2025, and the United States formally left the WHO on 22 January 2026.
Here is what happened in 2021, why it mattered to public health experts, and how the story ended.
What Biden actually did in January 2021
Leaving the WHO is not instant. When the Trump administration sent its notice to the United Nations in July 2020, it started a twelve-month countdown that would have ended in July 2021. Until then, the US remained a full member with all its rights and obligations.
Biden used that window. Among the first orders and letters he signed after the inauguration was a letter to UN Secretary-General António Guterres withdrawing the notice. The key line, as reported by CBS News, was simple: "The United States intends to remain a member of the World Health Organization."
So the accurate description is that Biden cancelled a pending withdrawal, rather than readmitting a country that had gone. The distinction became important in 2025, when a fresh notice had to be filed and the clock started again from zero.
Fauci's message in Geneva
The next day, 21 January 2021, Dr Anthony Fauci addressed the WHO Executive Board by video link. Fauci, then director of the US National Institute of Allergy and Infectious Diseases and Biden's chief medical adviser, led the American delegation.
He told the board that Washington would pay what it owed and resume normal work with WHO staff. He also announced that the United States would join COVAX, the WHO-backed scheme to buy and share Covid-19 vaccines with poorer countries, which the previous administration had refused to support.
The choice of Fauci was itself a signal. During 2020 he had often found himself at odds with the White House on pandemic messaging, including after Trump's widely criticised April 2020 musing about whether disinfectant or light could be used inside the body to treat the virus. Sending him to Geneva told other governments that scientific advice would once again shape US health diplomacy.
WHO Director-General Tedros Adhanom Ghebreyesus welcomed the news. "WHO is a family of nations and we are all glad that the United States is staying in the family," he said.
Why experts cared so much
The reaction from global health specialists was overwhelmingly positive, and for practical reasons rather than symbolic ones.
Money
The United States has long been the WHO's largest single funder, providing roughly 18% of its budget. The organisation is financed in two ways: assessed contributions, which are membership dues set by each country's wealth and population, and voluntary contributions, which are often earmarked for particular programmes such as polio eradication or emergency response. According to a 2026 US government fact sheet, American dues averaged about $111 million a year in recent years, while voluntary funding averaged about $570 million. Losing that in the middle of a pandemic would have left large holes in vaccination, surveillance and emergency programmes.
Information
The WHO runs networks that track influenza strains, share virus samples and coordinate outbreak alerts across 194 member states. Being inside those networks gives a country early warning about new threats. Experts quoted by USA Today at the time, including Thomas Bollyky of the Council on Foreign Relations and Lawrence Gostin of Georgetown's O'Neill Institute, argued that US interests were better served from inside the organisation, and that the WHO's weaknesses partly reflected chronic underfunding and weak political backing from its own members.
Influence
Members sit on the Executive Board, vote in the World Health Assembly and help shape global health rules such as the International Health Regulations. A country that walks away gives up its say in those decisions while still living with their consequences.
A short history of the WHO
The WHO is a specialised agency of the United Nations, created after the Second World War. Its constitution came into force on 7 April 1948, a date now marked every year as World Health Day, and its headquarters are in Geneva, Switzerland. The United States was a founding member.
The organisation's best-known success is the eradication of smallpox. A global commission certified the disease eradicated in 1979, and the World Health Assembly confirmed it in 1980. It remains the only human disease wiped out by deliberate effort, a campaign in which American scientists and money played a large part.
Its record is not spotless. Critics, including many who wanted the US to stay, have faulted its slow response to the 2014 West African Ebola outbreak and its early handling of Covid-19 in China. Supporters reply that the WHO has limited powers: it can advise and coordinate, but it cannot force any government to share data or let inspectors in.
The second withdrawal, 2025 to 2026
Biden's reversal lasted exactly four years. On 20 January 2025, the first day of his second term, Trump signed Executive Order 14155, starting a new withdrawal. The reasons given included the WHO's handling of the Covid-19 pandemic, what the administration called a refusal to adopt needed reforms, and a lack of independence from the political influence of member states.
The WHO said it regretted the decision and hoped the US would reconsider, pointing to decades of joint work. After the one-year notice period, the United States formally left on 22 January 2026, the first member state ever to do so. According to the US government fact sheet, all federal funding ended, American staff and contractors embedded with the WHO were recalled, and the country stopped taking part in WHO committees and technical working groups.
Some loose ends remain. The WHO says the US left with unpaid dues of roughly $260 million, a figure Washington disputes. Officials have said the country will pursue global health work directly with partner countries, outside WHO structures.
Common misunderstandings
- "The US left the WHO in 2020." It did not. The 2020 notice never took effect, because Biden withdrew it in January 2021. The actual departure came in January 2026.
- "Biden rejoined the WHO." Many headlines said this, but it is more precise to say he kept the country in.
- "The WHO can order countries to act." It cannot. It sets standards, coordinates and advises; national governments decide what to do.
- "Leaving saves only the membership fee." Dues were the smaller part of US funding. Most American money went through voluntary, programme-specific contributions.
What it means for ordinary people
For most readers, these decisions feel remote, yet they shape how quickly the next outbreak is spotted and how vaccines reach the countries that need them. Disease does not respect borders, and cooperation on surveillance, vaccine supply and emergency response tends to work best when the largest countries take part.
The 2021 episode is also a reminder that international commitments can swing with each election. A policy reversed on one inauguration day was reversed again on another, and the long-term effect on global health funding is still unfolding.
Sources: CBS News, Fauci underscores Biden's commitment to WHO (21 January 2021); USA Today, Scientists applaud Biden decision (22 January 2021); Executive Order 14155 (Wikipedia); CDC/HHS fact sheet: U.S. withdrawal from the World Health Organization; World Health Organization (Wikipedia).
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