China has stolen US military secrets to create formidable J-20 knockoff of America's F-22 Raptor: experts

Experts told Fox News Digital about the decades-long mission China has pursued to obtain comparable air force capabilities to the U.S. by using espionage to copy what they can.

"They have profited greatly from their thievery over the years," he said. "They've put it to good use, and they've come up with an advanced fifth-generation fighter," noting that it’s "hard to say short of actual combat" how the J-20 matches up against the U.S. F-22 Raptor fighter. Peter Aitken is a Fox News Digital reporter with a focus on national and global news. 

China began developing its J-20 in 2008 as part of a plan to design a new fighter that could compete with those in America. The plane first took flight in 2011, with its introduction to service in 2017.