In a surprising move, the U.S. has officially decided to leave the World Health Organization (W.H.O.), a decision that’s raising eyebrows among health experts. Many worry this could hurt America’s role as a leader in global health and make it tougher to tackle future pandemics. The announcement came on Monday, with President Trump finalizing the withdrawal. While not entirely unexpected—given his criticism of the W.H.O. during the COVID-19 crisis—the decision still sends shockwaves through the public health community. Here’s why it matters: The W.H.O. plays a key role in sharing critical health data worldwide. For example, when China first identified the genetic sequence of the coronavirus in 2020, it was the W.H.O. that quickly passed that information to other countries, including the U.S. Without access to this global network, experts fear the U.S. could be left in the dark during future outbreaks. The W.H.O. has also been working on a “pandemic treaty” aimed at improving global readiness for health crises. This includes faster data sharing, better vaccine production, and stronger supply chains. However, talks on the treaty stalled last year, with some U.S. lawmakers arguing it could threaten national sovereignty. Lawrence O. Gostin, a public health expert at Georgetown University, called the withdrawal “a grievous wound” to both global health and U.S. interests. Founded in 1948 with U.S. support, the W.H.O. has been instrumental in addressing major health challenges, from Ebola to Zika. The U.S. has been a major financial contributor to the W.H.O., which operates on an annual budget of about $6.8 billion. Withdrawing won’t happen overnight—Congress requires a year’s notice and payment of outstanding dues. Still, the move marks a significant shift in America’s approach to global health. As the world continues to grapple with health crises, the U.S. exit from the W.H.O. leaves many wondering what’s next for global cooperation in fighting diseases. ---