ONE CHILD NATION, documentary, rated R, 85 minutes, in English and Mandarin with subtitles, Center for Contemporary Arts,

If you’ve been thinking that this is a pretty rotten world but you weren’t absolutely sure, here’s a movie to confirm your worst suspicions.

For 35 years, from 1979 to 2015, China enforced a one-child policy to curb what had shaped up as catastrophic population growth. The public face of the policy was happy and positive, reinforced by wall-to-wall propaganda that appeared on billboards and murals, in children’s songs and schoolbooks, and through every conceivable medium. The image was a happy, smiling family: two parents, one child.

But the other side of the coin — the grotesque underbelly of the policy — was forced sterilization, forced late-term abortions, the punitive destruction of homes, the stealing and trafficking of “surplus” children, the collection of girl babies to sell to government orphanages for foreign adoptions, or their abandonment on roadsides, in markets, and in the trash.

Filmmaker Nanfu Wang was born in China in 1985, six years into the program, and accepted it as the status quo. It was only after she emigrated to the United States and became pregnant with her first child that she began to look critically at the one-child policy, and decided to undertake this documentary investigation.

What she and co-director Jialing Zhang uncovered will curdle your blood. An artist she interviews was inspired to create activist art when he came across a discarded fetus in a trash dump. A former government enforcer describes hog-tying and abducting young women to forcibly sterilize them. A man who spent 10 years in prison for human trafficking recalls collecting abandoned babies along the side of the road and selling them to state-run orphanages, where they were given falsified provenances and sold for big bucks on the international adoption market.

Some, like a midwife who estimates she performed 50,000 to 60,000 forced sterilizations and abortions, are steeped in remorse. Others defend the policy. “I had to put the national good above my personal feelings,” a former official smugly explains. “We were fighting a war.” Even Wang, growing up in that world, says she was only vaguely aware of the problems — that was just the way it was.

The picture is ugly, and the echoes are unmistakable — they reveal a population willingly ignorant of the horrors around them, officials who were “only following orders,” families separated, and children forcibly removed from their parents.

China ended the policy when it became clear there weren’t enough young people to take care of the old ones. There’s a new propaganda campaign these days: “One is too few, two is just right!” — Jonathan Richards