"If Korea raises tariffs, America's core industries will grind to a halt

Foreign media outlets claim, "If Korea raises tariffs, America's core industries will grind to a halt
Why did the Trump administration detain Koreans at that time?
They probably thought the factory was fully completed, so they wanted to set an example for Korea. But the incomplete construction probably left them feeling a bit helpless.
Samsung and other companies should also be cautious with their core technologies.