Why is China purging its nuclear missile force?

The top commanders of China’s nuclear forces have been targeted by President Xi Jinping in his latest purge, adding an extra layer of intrigue to the unexplained disappearance of Qin Gang, the country’s foreign minister.

On Monday, Chinese media announced that Wang Houbin, a former deputy commander in the navy, has been appointed head of the People’s Liberation Army Rocket Force, which oversees China’s conventional and nuclear missiles. This is the first time in 40 years that the top job has gone to somebody outside the unit. Li Yuchao, the previous head of the force, has been missing for weeks and several other top officers, including two of Li’s deputies, have also disappeared. China has said nothing about their whereabouts, but the South China Morning Post reports that they are being investigated by the Central Military Commission’s anti-corruption unit, citing military sources.