Why a terrorist attack is now 'probable'

It hasn’t raised the terrorism threat level for a decade, so why is ASIO increasing it now? The top spy body says a terrorist attack in Australia is now probable, up from possible.  More people holding extreme ideologies are leading to a ‘volatile and unpredictable’ security situation.  Today, we discuss what’s going on and how we should react, with counter-terrorism expert Lydia Khalil from the Lowy Institute.  Featured:  Lydia Khalill, program director of transnational challenges at the Lowy Institute