WASHINGTON — U.S. intelligence shows that China has conducted "human testing" on members of the People's Liberation Army in hope of developing soldiers with "biologically enhanced capabilities," the top U.S. intelligence official said Friday.John Ratcliffe, the director of national intelligence, included the explosive claim in a long Wall Street Journal op-ed in which he made the case that China poses the pre-eminent national security threat to the U.S.

"There are no ethical boundaries to Beijing's pursuit of power," wrote Ratcliffe, a Republican former member of Congress from Texas.His office and the CIA did not immediately respond to requests to elaborate on the notion that China sought to create "super soldiers" of the sort depicted in Hollywood films like "Captain America," "Bloodshot" and "Universal Soldier."Jean-Claude Van Damme, Dolph Lundgren and Tommy "Tiny" Lister line up in a scene from the 1992 movie "Universal Soldier."TriStar / Getty Images

Last year, two American scholars wrote a paper examining China's ambitions to apply biotechnology to the battlefield, including what they said were signs that China was interested in using gene-editing technology to enhance human — and perhaps soldier — performance.