As the Olympic Games kick off in Rio de Janeiro today, the risk of the Zika virus will undoubtedly cast a specter over the festivities. Some 500,000 tourists and 10,000 athletes are expected to participate and there are concerns that many may become infected with Zika, subsequently introduce the strain to their home countries, and set off a global pandemic. Yet the focus of attention may be in the wrong place: the discovery of 15 cases of Zika in the United States, in Miami, could ultimately have farther-reaching implications for fighting the virus.

According to the World Health Organization (WHO), the Brazilian fears have been greatly exaggerated. The organization declared the risk of Zika infection at the Olympics to be “low and manageable” and cases of the virus have declined substantially during the colder winter months—when the mosquito population typically falls off—down to roughly 200 per week compared to 8,000 during a peak in March.

The Miami discovery, meanwhile, marks the first time Zika has been transmitted via mosquitoes in the continental US, prompting the US Centers for Disease Control to issue an unprecedented domestic travel advisory to pregnant women. The news in Florida dovetails with a sharp rise in Zika cases in the northern hemisphere during the hot summer months, including in Mexico and the US territory of Puerto Rico, which saw an average of 855 cases per week during July.

The success of the global campaign against Zika may now depend on how the US strategy evolves in response to its own domestic threat. Washington could recognize the crisis as truly global and that stopping the spread at home means stopping the virus everywhere, as it did during the 2014-2015 Ebola crisis in West Africa. Alternatively, it could choose to neglect the needs of other countries as it races to address the outbreak in its territory, as occurred during the early stages of the HIV/AIDS epidemic in the 1990s.

There have indeed already been signs of a US retreat from its role as global leader in public health and pandemic response prior to the Florida cases. Further moves in this direction would go directly against what is needed to push back against Zika: a robust, sustained, and well-resourced international response led by the US and its regional allies, in partnership with multilateral institutions such as WHO and the United Nations.

Global Leadership

The US has until recently been at the forefront of global efforts to respond to Zika, including advancing scientific knowledge of the virus, according to Amesh Adalja, Senior Associate at the Center for Health Security at the University of Pittsburgh Medical Center. “From vaccine development to basic pathophysiological insights, the US—especially its scientists, physicians, researchers, and biotechnology companies—has been part of the vanguard,” he told me. The National Institutes of Allergy and Infectious Diseases developed the first experimental Zika vaccine and it is about to enter phase one clinical trials this week.

In addition to scientific research, the CDC has engaged its overseas counterparts to shore up the region’s defenses against the virus. These partners include a CDC office that has been based in Brazil since 2003, which has worked with the country’s Ministry of Health to build laboratory capacity and enhance outbreak surveillance and control. At a July meeting, US President Barack Obama and Mexican President Enrique Peña Nieto also agreed to strengthen cooperation in multiple areas pertinent to the Zika response, including research and sample sharing, outbreak surveillance, and mosquito abatement. This is in addition to regular coordination and communication with members of the US Global Health Security Initiative, which comprises the G7 countries, Mexico, and the European Commission.

Other US federal agencies have also implemented programs to halt Zika’s spread. In June, the US Agency for International Development (USAID) launched a $30 million anti-Zika initiative designed to spur innovation across the global community towards more effective mosquito control technology, personal protective equipment, and surveillance and diagnostic measures. In addition, the Obama administration’s $1.9 billion emergency funding request to Congress included $335 million for USAID to fund targeted countermeasures in Zika-affected countries, including mosquito abatement, maternal healthcare, and public health education. Obama requested an additional $41 million for the State Department to back global partners at WHO, the Pan American Health Organization, and UNICEF.

Backing foreign aid and development programs in this manner displays a keen understanding of the transnational nature of today’s disease threats. As noted in the January report of the UN High-Level Panel on Global Response to Health Crises, monitoring, preventing, and containing the spread of virulent pathogens requires looking beyond one’s own borders to supporting international cooperation and multilateral responses. The Ebola crisis in West Africa demonstrated how an inability to stop outbreaks at their source poses a risk to countries worldwide.

A Changing Tide?

Yet there are also signs that the US’s role as a global leader in the fight against Zika is increasingly in question. Notable among these is the ongoing failure of Congress to approve Obama’s emergency funding request. According to infectious disease expert Paul Farmer, it signifies a failure of US leadership to act on a global scale. It is tantamount to an isolationist attitude toward public health, especially at a time when the CDC estimates that Zika has spread to 67 countries and territories and is expected to infect up to 4 million people in the next year. As a consequence of the failure of Congress, the administration said in April it had to redirect $589 million designated for the Ebola crisis to the Zika response, posing a risk to West African countries still recovering from Ebola.

Moreover, since WHO declared Zika to be a Public Health Emergency of International Concern in February, the US and other global powers have shown limited appetite for supporting the Geneva-based organization and other multilateral efforts to respond to the outbreak.

In June, WHO announced its Zika Strategic Response Plan, a five-pronged strategy focused on detection, prevention, research, coordination, and socioeconomic care for families and communities. It will primarily be implemented by its UN and NGO partners, including UNICEF, which is already on the ground in 21 Zika-affected countries, providing reproductive healthcare, education, and counselling, as well as access to family planning services.

WHO estimates the plan will cost $122.2 million through 2017, but the US and other donor governments have given it less than $15 million as of July 27, calling into question their commitment to multilateral approaches to stamping out the virus. Meanwhile, the UN Zika Response Multi-Partner Trust Fund, established by UN Secretary-General Ban Ki-moon in May—in order to provide rapid and flexible funding to the response plan—had not received a single donation from member states as of July 27, according to the official website. This shortfall has forced WHO to borrow $3.8 million from a contingency fund it developed after the Ebola crisis.

In the aftermath of Ebola, world leaders pledged to strengthen the global health architecture under the leadership of WHO, by giving it the resources, organizational capacity, and institutional oversight to manage the next pandemic, as called for by the aforementioned UN high-level panel. Shortchanging WHO in this manner will likely make the task of its global listening post, the Global Outbreak Alert and Response Network, in monitoring and preventing Zika flare-ups even more difficult. This is concerning in light of recent warnings that Africa could be the next major Zika battleground.

Despite the prominence of Brazil in the coming weeks, international attention should be paid to the possibility of a shrinking US commitment to its overseas aid programs and regional partners, as it moves to confront its own outbreak. As various experts, studies, and panels have recently made clear, long-term multilateral action against the virus is necessary and US leadership could help insulate such efforts against irregular funding cycles and political gridlock.

Small and medium-sized countries in the Americas could pressure the US and other world powers to properly fund WHO and its UN partners so that they can continue working at the community level to mitigate Zika’s impact. Global health experts Anand Parekh and Ashish Jha, meanwhile, have proposed a federal aid program similar to the US President’s Emergency Plan for AIDS Relief, or PEPFAR. This multi-billion dollar partnership involving African countries, UNAIDS, WHO, and the private sector is believed to have saved millions of lives in sub-Saharan Africa since 2003.

The US has largely proven itself a capable leader in global efforts to control Zika to date. The world can ill-afford for it to be anything less at this critical stage in the fight against the virus.