China has conducted a new submarine-launched missile test, highlighting the growing reach of its sea-based nuclear deterrent. Fired from a Type-094 ballistic missile submarine into the South Pacific, the missile is widely believed to be the JL-3, capable of striking targets thousands of kilometres away. Analysts say the test demonstrates Beijing's improving second-strike capability and raises fresh concerns over the security of Guam and Hawaii amid rising Taiwan tensions. Why is this launch attracting global attention, and what does it reveal about China's expanding nuclear strategy?