In 2016, an American fertility doctor named John Zhang announced that he had gone to Mexico to quietly carry out the procedure on a woman from Jordan with a neurological disease called Leigh syndrome. She gave birth to a boy who appeared healthy. But she and her husband had no interest in letting scientists track the health of their child. We know nothing more of his fate.

This history echoed loudly this week, when Dr. He, an assistant professor at the Southern University of Science and Technology in Shenzhen, told the world that he had made gene-edited babies by altering the DNA of human embryos with a new technology called Crispr.

He cut out a small portion of DNA from a gene called CCR5. People who are missing this chunk of genetic material appear to be resistant to infections with H.I.V. Dr. He reasoned that genetically modified babies would resist the virus, too.

On Sunday, MIT Technology Review broke the news, followed by a lengthy story by The Associated Press. Dr. He posted a series of triumphant videos online, and on Wednesday, he went to a major gene-editing conference in Hong Kong to show slides with some details of his work.

Like the New Jersey fertility doctors before him, Dr. He was roundly condemned for his secretive recklessness. The organizers of the Hong Kong meeting issued a statement Thursday calling the birth of the twins “irresponsible.” They said Dr. He had designed the study poorly, and they labeled his ethical considerations a “failure.” Some scientists who watched Dr. He's talk wondered if he might have actually removed the wrong chunk of the CCR5 gene. The Chinese government called the procedure illegal and opened an investigation.

I got in touch with Glenn Cohen, a professor at Harvard Law School who studies reproductive technologies, to ask him to guess what happens next. His forecast sounded like a repeat of the mitochondrial replacement story.

“My sense of what will happen is that across the world there will be strong regulatory action,” Professor Cohen told me. He predicted a blanket ban of the technology. “People are scared, and when they are scared they make decisions that are not so subtle.”