By almost any yardstick, China’s one-child policy has been a grim failure. The Communist regime last week modified its notorious population-control program, announcing that married couples would henceforth be “allowed” to have two children. But the decision comes far too late to repair the damage the one-child policy caused, or to ease the unimaginable pain left in its wake.

Rarely has a government subjected its people to so dreadful a social experiment.

Futility was the least of its flaws. Imposed under Chinese ruler Deng Xiaoping in 1980, the one-child rule was envisioned as a spur to economic growth and a solution to the supposed problem of overpopulation. Yet by its own terms, it turned out to be almost wholly counterproductive. China’s fertility rate (the average number of children born per woman) had peaked at 6.2 in 1965, long before Deng came to power. By 1980, when the draconian policy was first rolled out, it had already dropped to 2.7. Without any government coercion, China’s 1960s-era baby boom had ended. Family size was gradually shrinking, as generally happens when living standards rise.

It took the one-child policy not to bring the national fertility level to a more manageable level, but to reduce it to a disastrous nadir. According to the 2010 Chinese census, the country’s fertility rate had sunk to 1.18, far below the 2.1 “replacement rate” necessary to keep a population from dwindling. In Beijing, Shanghai, and other large cities, the fertility rate is even lower: a microscopic 0.7.

But rather than put China on the track to prosperity as far as the eye can see, its plummeting birth rate means a rapidly aging population will have to be supported by a steadily diminishing workforce. As many demographers have said, China has been condemned to grow old before it grows rich. Today, there are five workers in China for every retiree. Within 15 years, the ratio will be a desperate 2 to 1. The one-child policy, defended by so many as the harsh-but-necessary medicine China needed to achieve economic vigor, turned out to be a poison pill.

Worse still, China’s one-child diktat condemned hundreds of millions of baby girls, born and unborn, to death.

In a country with an entrenched cultural preference for sons — based in part on the expectation that sons will be responsible for the support of elderly parents — the government’s policy led to an explosion of female infanticide, and then, with increased access to ultrasound machines, to sex-selective abortions. The Chinese government estimated recently that 13 million abortions are performed in the country annually. All told, population controls have resulted in a staggering total of 336 million abortions. One well-known consequence has been a drastic imbalance between the sexes. For every 100 newborn Chinese girls, there are 118 boys. That is a prescription for chaos: With more than 30 million so-called “bare branches” — young men unable to find female partners — China is heading for an upsurge in social pathologies ranging from rape to sex trafficking to drug and alcohol abuse.

But worst of all is the sheer brutality with which the one-child policy was applied.

Couples were forbidden to have a child before receiving government approval, and those who conceived without a permit were ordered to pay a massive fine or undergo an abortion. Women who resisted, many well into their third trimester, could be dragged to a clinic, strapped to a surgical table, and compelled to endure the killing of a baby they yearned for. Millions of Chinese women caught with a second child were forcibly sterilized. Others were publicly humiliated and fired from their jobs.

“It is not surprising,” writes Chinese author Ma Jian, who has chronicled the barbarities of the one-child policy, “that China has the highest rate of female suicide in the world.” It has been an unfathomable horror, and the scars will not soon heal.