One day last month, an Asiana Airlines flight sat on the tarmac at Incheon airport in Seoul, South Korea, waiting to push back from the gate for a routine flight across the Yellow Sea to China. The passengers had boarded; everything seemed normal.
But then several minutes passed, and nothing happened. The airplane door remained open. Finally, the voice of a flight attendant crackled over the intercom, “Could [passenger X] please come to the front of the plane?”
The passenger, a man in his forties surnamed Kim, rose from his seat and nervously moved forward. As he approached the cockpit, Mr. Kim was swarmed by airport police and South Korean intelligence agents, who escorted him off the plane and arrested him on the spot.
Buried in Mr. Kim’s luggage were no state secrets or military plans, but arguably something equally vital to Korea’s national security: manufacturing data for high-bandwidth memory (HBM) semiconductors.
