Shortly after his inauguration, President Donald Trump took a set of thick, black permanent markers and signed a sweeping set of executive orders that took aim at everything from immigration and gender to TikTok and climate change. One of his first moves was to withdraw the US from the World Health Organization (WHO), the United Nations’ global health agency responsible for safeguarding and promoting health around the world since 1948.

The US is one of the WHO’s biggest funders, so any shortage of financial and political support will likely have major ramifications for global health efforts like eliminating malaria, improving access to high-quality health care, and reducing maternal mortality. While that may not directly matter to rich countries like the US that have the means to address their own health challenges, one of the WHO’s most important jobs is to help coordinate the international response to pandemics and outbreaks — events that can threaten everyone, regardless of borders, as we learned during Covid-19.