China’s geopolitical rivalry with the West is expanding into new frontiers – including the polar regions, outer space, cyberspace and the deep sea – as Beijing unveils a flurry of scientific milestones and state-driven ambitions that analysts say are challenging traditional Western dominance across these critical domains. On Monday, China announced that its independently designed and built polar research vessel – the world’s first manned deep-sea-operations depot ship with icebreaking...