The United States has formally completed its withdrawal from the World Health Organization, ending a 78-year partnership forged after the ashes of World War Two.
Federal officials confirmed the break on Thursday, one year after President Donald Trump announced America would sever ties with the United Nations’ global health agency.
The departure, however, leaves unfinished business, with the United States owing more than $130 million in unpaid contributions, according to the WHO.
Administration officials also acknowledged unresolved issues, including the loss of access to international disease data that once offered early warnings of pandemics.
Public health experts say the exit weakens both global outbreak responses and America’s own scientific edge in developing vaccines and life-saving medicines.
“This is the most ruinous presidential decision in my lifetime,” said Lawrence Gostin, a public health law expert at Georgetown University.
The WHO coordinates global responses to threats like Ebola, polio and mpox, while guiding vaccine distribution and setting standards across hundreds of health conditions.
Nearly every nation belongs to the agency, which long counted the United States among its largest donors and most influential scientific partners.
Trump ordered the withdrawal shortly after taking office, accusing the WHO of mishandling COVID-19 and failing to resist political pressure from member states.
The organisation made serious pandemic errors, including early advice against masks and a delayed acknowledgment that COVID-19 spreads through the air.
U.S. officials also criticised the WHO’s leadership history, noting no American has ever served as director-general despite decades of heavy U.S. funding.
Experts warn the withdrawal could cripple polio eradication, maternal health programmes, and global surveillance systems that track emerging viral threats.
The United States has already left WHO committees that monitor circulating flu strains and help determine the composition of annual vaccines.
Such intelligence once placed American researchers at the front of the line when outbreaks struck and new treatments were urgently needed.
Officials say Washington is seeking direct data-sharing agreements with other countries, though they offered few details on how many exist.
Gostin called that strategy unrealistic, questioning whether nations such as China or several African states would bypass the WHO to share sensitive information.
The WHO says U.S. law requires Washington to settle outstanding debts, a claim the administration disputes as it closes the door.
As the world braces for the next unknown pathogen, the rupture leaves a hollow echo where American influence once guided global health cooperation.