How extremism and foreign interference threaten Australian social cohesion

The threats posed by sovereign citizen views materialised again this week with the killing of two police officers in Victoria's north-east by the alleged gunman Dezi Freeman, who remains at large.In the same week, an ASIO investigation found that Iran was ultimately responsible for an attack on a Melbourne synagogue, and an arson attack on the Lewis Continental Kitchen in Sydney, and potentially many other violent acts of anti-Semitism in Australia.How do we respond to both internal and external threats to national security and social cohesion?