The Chinese gene-editing experiment was an outrage. The scientific community shares blame.

This is the experiment that was not supposed to happen.

A Chinese scientist claimed this week that he had produced the first genetically engineered babies — twin girls who have been “edited” to be resistant to HIV. He and his collaborators, who apparently include a professor at Rice University in Houston, allegedly applied the genome editing tool known as CRISPR to embryos produced through in vitro fertilization to modify a gene called CCR5. The purpose of the edit was to prevent future HIV infection, a move akin to a genetic vaccination.

Three years ago, scientists, social scientists and ethicists gathered in Washington at the National Academy of Sciences for the first international summit on human gene editing, to discuss scientific, social and ethical issues surrounding human applications of this powerful new tool. One result of the meeting was a call for a voluntary international moratorium on reproductive applications of genome editing until there was “broad societal consensus” about when making such heritable modifications is ethically acceptable.

Nothing remotely like a consensus has been reached, yet the research races ahead. Numerous...