The United States has a narrow window of opportunity to determine the fate of its coronavirus crisis. Will we end up looking like Italy or South Korea?

Italy’s health system has imploded under the strain of new cases and the shortage of ventilators means doctors must make agonizing decisions on who to save and who to let die. In contrast, South Korea acted swiftly and boldly to “flatten the curve”— the government did everything it could to slow the rate of increase and so reduce the burden of the illness on the country’s clinics and hospitals.

Why is it so critical for us to have a massive surge in testing? People who are sick need to get the right diagnosis and clinical care. People with mild symptoms who get tested can self-isolate and help stop the spread of the virus. If one person has the disease, we can then test those they have been in contact with (known as “contact tracing”). In other words, testing and contact tracing can help to break the chain of transmission. As Dr Tedros Ghebreyesus, the World Health Organization’s director general, says: “Find, isolate, test and treat every case, and trace every contact.” And, crucially, testing helps us to know where the disease is, how it is evolving, and where to target our efforts to control it. It identifies the hot spots of infections.

Countries that have flattened the curve made testing widely and freely available, using innovative approaches like mass drive-thru test centers. South Korea has been conducting around 12,000-15,000 tests every day, and has the capacity to do 20,000 daily. While it is hard to get accurate estimates, the CDC reports that only around 25,000 tests have been conducted in total nationwide by CDC or public health labs in the U.S.—compare this with the roughly 250,000 tests that South Korea has done to date.

A critical tool for breaking this community transmission is “social distancing”—staying away from places where people congregate (movie theaters, bars, restaurants, shopping centers), avoiding mass gatherings (like religious services and concerts), and maintaining a distance of at least six feet from other people. Countries that flattened the curve have taken a variety of approaches to breaking community transmission, from school and office closures to suspending public transportation.

Our most precious resource right now is our health workers. To prevent the medical workers from becoming infected, sufficient protective equipment should be supplied to ensure their safety. Such infections put even more strain on the health system, and continue to fuel the cycle of transmission.

All in all, it’s too soon to throw in the towel and accept an Italian scenario. With five key measures—testing and contact tracing, communication and coordination, social distancing, protecting health workers, and health systems planning—we could still become South Korea.