By the time the world began responding to the West Africa epidemic in 2014, which killed more than 11,000 people before it ended in 2016, there were 40 to 50 suspected cases. The current outbreak in the Democratic Republic of the Congo had approximately 10 times that number by the time the response started. Three weeks in, it has spread from three health zones to 25, with new areas added almost daily. National, provincial, and local health staff are responding intensively, but fewer than half of known contacts are being traced nationwide, laboratories are backlogged, no Ebola treatment center is ready, few health workers have been trained, there’s insufficient protective equipment for health workers and few medications for patients, and burial teams have come under attack. The virus has a running head start, and every minute counts. With Ebola, time is lives. Get to an outbreak in days and you can stop it in weeks. Get there in weeks and it goes on for months. Get there in months and it can go on for years. I led the CDC response to the 2014–2016 West Africa epidemic. I told the U.S., on camera, that any American hospital could safely care for an Ebola patient. Then a Dallas hospital sent a man home who had just arrived from Liberia with a fever. When he returned two days later, gravely ill, two nurses were infected. Three cases nearly overwhelmed us, while 3,000 raged in Liberia. That mistake nearly cost me my job — and, more importantly, could have cost lives. Ebola is an unforgiving enemy. One unprotected nurse can start a new chain of transmission. One unsafe burial can seed hundreds of cases. The work of containing it is meticulous and exhausting: for clinicians in full protective gear in tropical heat, for contact tracers who must find every person a patient touched, for the epidemiologists who must track every cluster, and for the community workers who must explain terrifying facts to patients, families, and communities. This outbreak began in a gold-mining hub in Ituri and spread along travel routes before it was caught, and it’s spreading in places where more than 100 armed groups operate. Ebola is hard to control in the best of conditions. It’s close to impossible to control when people are shooting at you. There’s no vaccine or proven treatment for this strain — but that was true in 2014, and the response stopped it anyway. Supportive care saves lives. Contact tracing, quarantine, and rapid isolation control spread. A vaccine and treatment are urgently needed, but we can control the outbreak without them — if the world acts right now. The most experienced people at stopping Ebola are the doctors, nurses, and epidemiologists of DRC and Uganda. They’ve done it before; what’s different now is the scale needed. DRC needs surge support, including clinicians, labs, infection-control specialists, logistics, and funding for community health workers and for substantial community support (food, medicines, bed nets, clean water). Communities respond to Ebola the way humans respond to any terrifying disease: with fear, denial, and sometimes violence. Only trusted community leaders can persuade the sick to seek care, identify their contacts, and adapt the burial practices that spread the virus. The world has to show that we care about the affected communities, not just the virus. Laboratories must confirm cases within hours, treatment units must be staffed within days, and surveillance teams must find every suspected case and contact and follow each for 21 days. In West Africa, 90% of responders came from the affected communities themselves, and that will be true again. The world’s job is to enable the people closest to the virus to do the work. The last epidemic also showed the route to success. The early response to a traveler who carried Ebola into Lagos, Nigeria, a city of more than 20 million, faltered — until incident management turned it around, breaking an overwhelming problem into manageable units. Within days a trained team made thousands of home visits and held the outbreak to 19 cases. The same discipline is needed now, at far greater scale. In a Wednesday op-ed in the Wall Street Journal, acting CDC Director Jay Bhattacharya outlined three aims for the U.S. response: keep Ebola out of the United States, care for Americans in the region who fall ill, and help DRC contain the outbreak. The first two are understandable, although travel restrictions and an evacuation ward are inevitably imperfect. The only complete and durable protection for Americans is an outbreak stopped in DRC. What the U.S. government says about its response matters less than what it does. Stopping it at the source takes immediate and substantial surge support from the CDC, including laboratories, genomic sequencing, and disease detectives, and also the community funding and logistics that USAID and the Pentagon provided in the past. In 2014, CDC mounted the largest response in its history: 50 specialist staff in the outbreak zone within two weeks, ultimately 200 across West Africa at a time, 400 running an emergency operations center in Atlanta, and more than 110,000 workdays in all. USAID funded some 190 safe-burial teams, extensive community support, and the salaries of thousands of frontline health workers. The Department of Defense built treatment units, ran an air bridge through Senegal that flew in more than 10,000 tons of supplies, and opened a hospital to protect infected local health workers. The U.S. government probably cannot put staff on the frontlines in DRC because of security concerns. But laboratory confirmation, genomic sequencing to track the strain, the epidemiological analysis that steers the response, and more can be supported from the national and some provincial capitals. It’s what the United States once did best, but it is unclear whether the CDC, despite still having thousands of dedicated staff, has the capacity, support, and mandate to do that today. And the State Department and Pentagon can surge support for health workers and communities in affected areas. Bhattacharya is running the agency part time while also leading the National Institutes of Health. Nearly all of CDC’s top leadership positions are now filled by acting or part-time appointees, or sit vacant. The CDC has lost close to 3,000 scientists, doctors, and experts in 18 months. The United States has withdrawn from the World Health Organization, withheld its dues, and abruptly recalled American specialists who worked with WHO. On May 5, the State Department directed CDC not to renew contracts that deliver HIV care to more than 8 million people, the contracts that also support laboratory and monitoring systems, and outbreak surveillance. USAID, which once surged the flexible money that supports communities and builds trust, has been dismantled. A broader State Department proposal could cut up to 85% of CDC’s overseas work and let countries order the rest à la carte, but you can’t order à la carte if the restaurant is closed. We need a stronger WHO, a rebuilt CDC, and better detection and response everywhere. Global health is a win-win: Every country is safer when all find outbreaks faster and stop them sooner. Another pandemic will come. We don’t know the pathogen, place, or year, but the most important question is whether we marshal the resources, leadership, and collaboration in time. This outbreak is a stress test — and right now, despite recent progress, the world is failing. Ebola could be controlled in months. But if a massive response doesn’t happen in days, success could take years. Massive. Immediate. Meticulous. Tom Frieden was director of the U.S. Centers for Disease Control and Prevention from 2009 to 2017 and is president and CEO of Resolve to Save Lives, a global health organization.