What’s behind China’s ballistic missile test?

On Monday, China’s military launched a nuclear capable ballistic missile over the Pacific Ocean from a submarine hidden in the sea off China.  It gave Australia and other nations about 24 hours’ notice.   So, what’s XI Jinping up to?   Today, Sam Roggeveen from the Lowy Institute on China’s massive expansion of its nuclear arsenal and what it means for us.  Featured:   Sam Roggeveen, director of the International Security Program at the Lowy Institute