Much of what is said about the inner workings of the North’s government is speculation. The dictatorial regime’s isolationist policies ensure that its politics are shrouded in secrecy. Kim Jong-nam, as the eldest son of late leader Kim Jong-il, was at one time destined to succeed his father. But he spent most of his time overseas, usually in Macau, and in 2001 caused embarrassment by being detained while trying to enter Japan on a false passport. Kim Jong-il remarried in the late 1970s and his new wife became powerful within the government and her youngest child, Kim Jong-un, was manoeuvred into the leadership.

Whether Kim Jong-nam lived overseas out of choice or because he was exiled is not clear. More definite is that in recent years he was a critic of the North’s political system, voicing disapproval of dynastic governance. How much support he had at home is unknown, but there is no disputing that opposition is not tolerated by the regime. Not even relatives are immune, as shown in 2013 when the brothers’ uncle, Jang Song-thaek, once considered the country’s second most powerful person, was executed for treason.

The leadership has gone to great lengths to get rid of rivals. It has a record of using assassins to kidnap, murder or bomb overseas targets. Among the victims have been South Korean politicians, Japanese citizens and aircraft passengers. At home, the paranoia of staying in power has led since the founding of North Korea to the deaths or imprisonment in labour camps of opponents estimated to number in the hundreds of thousands.