On January 20, 2025, President Donald Trump signed an executive order initiating the United States’ withdrawal from the World Health Organisation (WHO). This decision has significant implications, particularly concerning infectious diseases, disease surveillance, and international health funding.

This seismic shift in global health policy carries far-reaching impacts on public health, international collaboration, and geopolitics. At its core, this decision reflects a fundamental reassessment of the United States’ role in multilateral organisations, framed within the context of sovereignty and fiscal priorities. However, this choice also lays bare the complex interplay of consequences that extend well beyond U.S. borders, potentially reshaping the global health landscape for years to come.

From the perspective of infectious disease control, the U.S. withdrawal could significantly impair global efforts to prevent, detect, and respond to outbreaks. The WHO serves as the primary international body for coordinating responses to emerging health threats, ranging from pandemics like COVID-19 to diseases such as Ebola, Zika, and avian influenza. The U.S. has traditionally played a pivotal role in these efforts, contributing expertise, technology, and funding to initiatives that strengthen disease surveillance systems and ensure equitable access to vaccines and treatments. By stepping away, the U.S. risks losing access to critical data and resources that underpin its own public health preparedness. Infectious diseases do not respect borders, and the weakening of global systems to monitor and contain such threats could ultimately rebound on the U.S., jeopardising its own citizens’ health and security.

The financial implications of this decision are equally profound. The U.S. has been the largest single contributor to the WHO, providing approximately 18% of its total budget. This funding underpins vital programmes that target some of the world’s most pressing health challenges, including efforts to eradicate polio, combat HIV/AIDS, and address maternal and child health in low-income countries. Without U.S. contributions, these programmes face an uncertain future. While other nations may attempt to fill the funding gap, the scale of the shortfall could lead to delays, reductions in scope, or outright cancellations of critical interventions. For populations in resource-poor settings, the consequences could be devastating, with increased mortality and morbidity rates for diseases that are otherwise preventable or treatable.

Critics of the decision have also raised concerns about the potential erosion of international cooperation in health governance. The WHO, despite its flaws, serves as a unique platform for bringing together nations to address common challenges. U.S. withdrawal risks undermining the multilateral spirit that is essential for tackling global health threats, fostering a more fragmented and less coordinated approach to international health crises. This move may embolden other countries to prioritise national interests over collective action, weakening the global health system at a time when it faces unprecedented challenges, including climate change-induced health risks and antimicrobial resistance.

Supporters of the decision argue that the WHO has been inefficient and politically compromised, particularly in its handling of high-profile crises such as the COVID-19 pandemic. They contend that U.S. funds could be better utilised through bilateral initiatives or by supporting alternative health programmes that align more closely with American strategic priorities. This argument, however, overlooks the unique role that the WHO plays in setting international health standards, fostering technical cooperation, and ensuring that all countries, regardless of their economic standing, have a voice in shaping the global health agenda. While reforms to the WHO may be warranted, withdrawal represents a blunt instrument that does little to address the underlying issues and instead risks exacerbating existing inequities in global health.

The geopolitical ramifications of this decision cannot be ignored. By withdrawing, the U.S. cedes ground to other nations, particularly China, which has increasingly sought to expand its influence within the WHO and other international organisations. This shift could lead to a reorientation of global health priorities, with potential implications for the transparency, accountability, and inclusiveness of international health governance. The U.S. withdrawal thus not only diminishes its own influence but also reshapes the balance of power in ways that may not align with its long-term strategic interests.

In assessing this decision, it is crucial to consider the broader context of global health policy and the interconnectedness of modern health challenges. Infectious diseases, climate change, and rising health inequities are transnational issues that demand coordinated, collective responses. The U.S. has historically been a leader in addressing these challenges, leveraging its resources and expertise to drive progress on a global scale. The withdrawal from the WHO represents a retreat from this leadership role, raising fundamental questions about the nation’s commitment to global health solidarity and its willingness to engage with the international community in tackling shared threats.

Ultimately, the decision to withdraw from the WHO is emblematic of a broader trend toward unilateralism and disengagement from multilateral institutions. While this approach may resonate with certain domestic constituencies, its long-term implications for global health security and international relations are deeply concerning. The COVID-19 pandemic demonstrated the importance of strong, collaborative international health systems, and the U.S. withdrawal risks undermining the very mechanisms needed to prevent future crises. At a time when global health challenges are becoming ever more complex and interconnected, the decision to step back from the WHO is a gamble with potentially catastrophic consequences, not only for the world but for the United States itself.