China is beginning “mass production” of fifth-generation J-20B stealth fighter jets in a bid to seize control of the local airspace from neighboring U.S. allies.

“It’s going to be really hard for us to keep up with the numbers that China’s going to have,” said the American Enterprise Institute’s Zack Cooper, a former Pentagon official who specializes in U.S.-China military competition. “That’s going to be a really big struggle.”