China’s New Chip Ban on Micron Puts South Korea in a Delicate Spot

South Korea, an American ally, is home to Micron’s two largest rivals in the memory-chip business, Samsung and SK Hynix. A new Chinese clampdown on American chip giant Micron Technology MU 0.89%increase; green up pointing triangle has put South Korea in an uncomfortable position. Amid a series of tit-for-tat trade moves between Beijing and Washington, China, citing national-security risks, banned certain local firms in key information-infrastructure industries from buying memory chips from Micron. The clampdown affects parts of Micron’s roughly $3 billion in annual sales from China. South Korea, a...