It’s a growing problem that has United States naval commanders scratching their heads: How to keep up with China’s ever-expanding fleet of warships. Not only is China’s navy already the world’s largest, its numerical lead over the US is getting wider, with the head of the US Navy warning recently that American shipyards simply can’t keep up. Some experts estimate China can build three warships in the time it takes the US to build one. It is just one of the concerns, alongside Beijing’s increasing aggression in the South China Sea and around Taiwan, that’s likely to be weighing on...