CHANGWON, South Korea: At the outskirts of a South Korean industrial city, workers at a sprawling weapons factory were conducting final-stage testing for a newly built surface-to-air defence system that could, eventually, head to Ukraine. Longstanding domestic policy bars Seoul from sending weapons into active conflict zones, but ever since its spy agency accused the nuclear-armed North last month of sending thousands of soldiers to help Moscow fight Kyiv, South Korea has warned it might change