O ne is internationally famous – he was once dubbed “the Face of Protest” by Time magazine – and the other is little known outside his home town. What Joshua Wong and Au Kam San share, beyond the harsh sentences they received last week, is that they represent the spirit of dissent that Beijing is determined to crush.

Mr Wong , who has been in prison for six years, should have walked free next January – not free to fight for Hong Kong’s rights, which China has suppressed so decisively, but at least to walk the streets of the city he loves. Instead, a court last Thursday sentenced the 30-year-old, an activist from the age of 14 , to another 10 years . He is the only person to have been prosecuted twice under the draconian national security law (NSL). The case’s timing means that he will remain behind bars until he is 40 because so little of his sentences overlap.…