A 20-minute drive from the South Korean city of Daegu sits the Gumi Industrial Complex. Home to more than 2,600 companies and production plants, it looks like any manufacturing hub in a small quiet town. But over the past two decades its global importance has grown almost unnoticed as Apple and its rivals in Asia have concentrated production of vital components — for everything from smartphones to TVs, and the drivers of cloud computing — in the area.

Coronavirus is now exposing how risky that strategy was and how vulnerable the smartphone supply chain is: Daegu is at the centre of the South Korean outbreak of the pandemic, with 85 per cent of the country’s 8,413 cases.

Samsung Electronics and LG Electronics, central to South Korea’s postwar economic miracle, are the world’s largest suppliers of memory chips, organic light emitting diode (OLED) displays and camera modules. Production of these essential components is concentrated in a handful of locations around Gumi and the Seoul suburbs.