As many Global North countries turn inwards, foreign assistance has become an easy target. The decimation of the US Agency for International Development (USAID) has dominated headlines, but the United Kingdom and many European countries have also cut their foreign-aid budgets. Policymakers in these countries view this spending as a form of charity and think that bolstering their economic and military might can deliver more benefits for more people.
This instinct is short-sighted. It recalls the great-power ambitions of the nineteenth and early twentieth centuries that culminated in two devastating world wars. The global governance architecture that emerged from this unprecedented tragedy initially focused on responding to reconstruction needs and humanitarian crises, before turning to development. Despite its flaws, this approach helped lift more than one billion people out of extreme poverty and build stable and thriving economies around the world.
The global health system is a case in point. Built with funding from the United States, the United Kingdom and other wealthy countries, it has substantially reduced infectious disease rates and health inequalities, creating a safer and more secure world. Five years ago, this system was instrumental in detecting Covid-19, tracking its spread and mobilising a global response.
But Covid-19 also illustrated how poorer countries and households are caught in an inequality-pandemic cycle. After compiling and analysing hundreds of peer-reviewed studies, the Global Council on Inequality, Aids and Pandemics (of which we are members) found that poor and marginalised people struggle to access health services during disease outbreaks, leaving them more susceptible to infection, illness and death.
In the early days of Covid-19, this inequality-pandemic cycle was on display in Global North countries. White-collar professionals worked safely from home, thanks to high-speed internet and teleconferencing platforms, whereas small businesses and factories closed, throwing blue-collar workers into financial crisis. In these countries, the pandemic hit low-income and black and minority communities the hardest.
The unequal impact of the pandemic was also felt between countries. Vaccines were developed in record time, but high-income countries purchased most of them and then refused to share excess doses with the developing world. This vaccine hoarding caused more than 1 million deaths and cost the global economy an estimated US$2.3 trillion (76.6 trillion baht).
The same pattern played out in the early response to the Aids pandemic. At the end of the 20th century, effective antiretroviral drugs became available in the Global North. But Aids continued to kill hundreds of thousands of people in the Global South, and especially in Sub-Saharan Africa. The unconscionable denial of access to lifesaving treatment sparked global outrage, leading to the establishment of the Joint United Nations Programme on HIV/Aids (UNAIDS), the Global Fund to Fight Aids, tuberculosis and malaria and the President's Emergency Plan for AIDS Relief (Pepfar) in the US. In 2002, fewer than 1 million people living with HIV had access to antiretrovirals, whereas more than 30 million do today; expanding access to treatment has so far saved an estimated 26 million lives. And, before the recent foreign-aid cuts, the world could have achieved its goal of ending Aids as a public health threat by 2030.
The decades-long journey to end Aids has underscored the importance of investing in health systems, medical research and vaccine and drug production in both the Global North and the Global South. Moreover, it has highlighted that people's living conditions -- often called the social determinants of health, including job security, income level, access to education, affordable housing and respect for rights -- determine their well-being.
For example, in 1996, Botswana, which was hit particularly hard by the Aids pandemic, effectively added a year of secondary school to its public education system. This policy created a natural, population-level experiment on the effect of schooling on the risk of HIV infection. An analysis of huge cohorts of young people who went to school under the old system and the new system found that each additional year of schooling reduced young people's risk of HIV infection by 8.1 percentage points. This protective effect was strongest among women, whose risk of contracting HIV decreased by 11.6 percentage points for each additional year of school.
Building fairer societies leads to healthier populations that are better prepared to react to disease outbreaks and prevent pandemics. By contrast, defunding public education, imposing tariffs, closing borders, cutting foreign aid and disengaging from multilateral cooperation will widen inequalities, accelerate economic migration and create the conditions for viruses to thrive.
This is evident in Ukraine, where an overburdened health-care system has accelerated the spread of drug-resistant infections through war-torn communities. Meanwhile, outbreaks of Ebola, mpox, measles and Marburg are on the rise, partly owing to globalisation and climate change. Weakening the global health system will enable these outbreaks to fester and spread, taking lives, deepening inequalities and potentially destabilising societies. Experts are already warning that cuts to US programmes (including those delivered by USAID) could lead to a 400% increase in Aids deaths by 2029.
The abiding lesson of pandemics is that no one is safe until everyone is safe. Building walls and shutting out the world will not protect people. The only way to do that is by reducing inequalities and investing in the global health system. In this context, cooperation is the ultimate act of self-interest. ©2025 Project Syndicate
Winnie Byanyima is the Executive Director of UNAIDS and an Under-Secretary-General at the United Nations. Michael Marmot is Director of the Institute of Health Equity and Professor of Epidemiology at University College London.