Unlike other countries, it has so far avoided both isolation and economic ruin.

If the COVID-19 pandemic tails off in a few weeks, months before the alarmists claim it will, they will probably pivot immediately and pat themselves on the back for the brilliant social-distancing controls that they imposed on the world. They will claim that their heroic recommendations averted total calamity. Unfortunately, they will be wrong; and Sweden, which has done almost no mandated social distancing, will probably prove them wrong.

Lots of people are rushing to discredit Sweden’s approach, which relies more on calibrated precautions and isolating only the most vulnerable than on imposing a full lockdown. While gatherings of more than 50 people are prohibited and high schools and colleges are closed, Sweden has kept its borders open as well as its preschools, grade schools, bars, restaurants, parks, and shops.

President Trump has no use for Sweden’s nuanced approach. Last Wednesday, he smeared it in a spectacular fashion by saying he’d heard that Sweden “gave it a shot, and they saw things that were really frightening, and they went immediately to shutting down the country.” He and the public-health experts who told him this were wrong on both counts and would do better to question their approach. Johan Giesecke, Sweden’s former chief epidemiologist and now adviser to the Swedish Health Agency, says that other nations “have taken political, unconsidered actions” that are not justified by the facts.

In the rush to lock down nations and, as a result, crater their economies, no one has addressed this simple yet critical question: How do we know social-isolation controls actually work? And even if they do work for some infectious epidemics, do they work for COVID-19? And even if they work for this novel coronavirus, do they have to be implemented by a certain point in the epidemic? Or are they locking down the barn door after the horses are long gone?

In theory, less physical interaction might slow the rate of new infections. But without a good understanding of how long COVID-19 viral particles survive in air, in water, and on contact surfaces, even that is speculative. Without reliable information on what proportion of the population has already been exposed and successfully fought off the coronavirus, it’s worth questioning the value of social-isolation controls. It is possible that the fastest and safest way to “flatten the curve” is to allow young people to mix normally while requiring only the frail and sick to remain isolated.

This is, in fact, the first time we have quarantined healthy people rather than quarantining the sick and vulnerable. As Fredrik Erixon, the director of the European Centre for International Political Economy in Brussels, wrote in The Spectator (U.K.) last week: “The theory of lockdown, after all, is pretty niche, deeply illiberal — and, until now, untested. It’s not Sweden that’s conducting a mass experiment. It’s everyone else.”

We’ve posed these simple questions to many highly trained infectious-disease doctors, epidemiologists, mathematical disease-modelers, and other smart, educated professionals. It turns out that, while you need proof beyond a reasonable doubt to convict a person of theft and throw them in jail, you don’t need any actual evidence (much less proof) to put millions of people into a highly invasive and burdensome lockdown with no end in sight and nothing to prevent the lockdown from being reimposed at the whim of public-health officials. Is this rational?

When we asked what evidence is available to support the utility of quarantine and social isolation, academics point to the Diamond Princess cruise ship, with 700 COVID-19 passenger cases and eight deaths. But the ship is an artificially engineered, densely packed container of humans that bears little resemblance to living conditions in most countries.

The other major evidence academics often cite is the course run by the 1918 swine flu, which swept the globe 102 years ago and was not a coronavirus. Philadelphia did not practice social distancing during the 1918 pandemic, but St. Louis did and had a death rate lower than Philadelphia’s. But how is that relevant to today’s crisis? Apart from the post hoc, ergo propter hoc nature of the argument, a key difference was that the GIs returning from World War I Europe who were carrying the swine-flu virus couldn’t fly nonstop from Paris to St. Louis. They had to land at East Coast ports such as Philadelphia. It’s therefore not surprising that the sick GIs rested and convalesced while spreading the virus on the East Coast, and they got better before continuing to St. Louis and other interior cities.

Basing the entire architecture of social distancing on the evidence from the 1918 swine flu makes no sense, especially when that architecture causes significant destruction in the lives and livelihoods of most of the American population.

But the social-isolation advocates frantically grasp at straws to support shutting down the world. It bothers them that there is one country in the world that hasn’t shut down and that hasn’t socially isolated its population. It bothers them because when this coronavirus epidemic is over, they would probably love to conclude that social isolation worked.

Sweden has courageously decided not to endorse a harsh quarantine, and consequently it hasn’t forced its residents into lockdown. “The strategy in Sweden is to focus on social distancing among the known risk groups, like the elderly. We try to use evidence-based measurements,” Emma Frans, a doctor in epidemiology at Sweden’s Karolinska Institute, told Euronews. “We try to adjust everyday life. The Swedish plan is to implement measurements that you can practice for a long time.”

The problem with lockdowns is that “you tire the system out,” Anders Tegnell, Sweden’s chief epidemiologist, told the Guardian. “You can’t keep a lockdown going for months — it’s impossible.” He told Britain’s Daily Mail: “We can’t kill all our services. And unemployed people are a great threat to public health. It’s a factor you need to think about.”

If social isolation worked, wouldn’t Sweden, a Nordic country of 10.1 million people, be seeing the number of COVID-19 cases skyrocket into the tens of thousands, blowing past the numbers in Italy or New York City? As of today, there are 401 reported COVID-19 deaths in Sweden.

The really good news is that in Sweden’s ICU census, which is updated every 30 minutes nationwide, admissions to every ICU in the country are flat or declining, and they have been for a week. As of this writing (based on currently available data), most of Sweden’s ICU cases today are elderly, and 77 percent have underlying conditions such as heart disease, respiratory disease, kidney disease, and diabetes. Moreover, there hasn’t been a single pediatric ICU case or death in Sweden — so much for the benefits of shutting down schools everywhere else. There are only 25 COVID-19 ICU admissions among all Swedes under the age of 30.

Sweden is developing herd immunity by refusing to panic. By not requiring social isolation, Sweden’s young people spread the virus, mostly asymptomatically, as is supposed to happen in a normal flu season. They will generate protective antibodies that make it harder and harder for the Wuhan virus to reach and infect the frail and elderly who have serious underlying conditions. For perspective, the current COVID-19 death rate in Sweden (40 deaths per million of population) is substantially lower than the Swedish death rate in a normal flu season (in 2018, for instance, about 80 per million of population).

Compare that with the situation to Switzerland, a similar small European country, which has 8.5 million people. Switzerland is practicing strict social isolation. Yet Switzerland reports 715 cumulative Wuhan-virus deaths as of today, for a death rate nearly double the number in Sweden. What about Norway, another Nordic country that shares a 1,000-mile open border with Sweden, with a language and culture very similar to Sweden’s? Norway (population 5.4 million) has fewer reported COVID-19 deaths (71) than Sweden but a substantially higher rate of coronavirus ICU admissions.

On Friday, one of us spoke with Ulf Persson in his office at the Swedish Institute for Health Economics. He said that everyone he knows is calm and steady, behaving with more caution than normal, following such government-mandated social controls as a 50-person limit on gatherings and only sit-down service at bars and restaurants. Persson estimates that the Swedish economy will drop about 4 percent because of the global economic shutdowns. But that’s nothing compared with the Great Depression unemployment levels of 32 percent that the U.S. Federal Reserve Board of St. Louis recently forecast for the United States.

Nature’s got this one, folks. We’ve been coping with new viruses for untold generations. The best way is to allow the young and healthy — those for whom the virus is rarely fatal — to develop antibodies and herd immunity to protect the frail and sick. As time passes, it will become clearer that social-isolation measures like those in Switzerland and Norway accomplish very little in terms of reducing fatalities or disease, though they crater local and national economies — increasing misery, pain, death, and disease from other causes as people’s lives are upended and futures are destroyed.

John Fund is a columnist for National Review and has reported frequently from Sweden. Joel Hay is a professor in the department of Pharmaceutical Economics and Policy at the University of Southern California. The author of more than 600 peer-reviewed scientific articles and reports, he has collaborated with the Swedish Institute for Health Economics for nearly 40 years.