What do Hong Kong mass arrests mean for democracy movement?

Banners of pro-democracy candidate Joshua Wong, wearing glasses, are displayed outside a subway station in Hong Kong (Vincent Yu/AP)

The sudden arrest of dozens of pro-democracy activists in Hong Kong, in the most sweeping use of a new national security law to date, is a clear sign of Beijing’s determination to rein in political opposition in the former British colony.

The roundup, widely condemned by Western government officials and human rights groups, is likely to further chill an already dwindling protest movement in the semi-autonomous Chinese territory.