SYDNEY - The dramatic siege in Sydney follows months of warnings about "lone wolf" attacks, and experts say the authorities must think harder about how to tackle the problem.
The incident at the Lindt cafe comes amid a backdrop of warnings from the Australian government about radicalised Muslims, potentially attracted to the conflicts in Iraq and Syria, and sympathising with the Islamic State of Iraq and Syria (ISIS) group.
Australia has committed some 600 troops and several aircraft to Iraq. In September, it upgraded its security alert in the face of extremist threats, ramping up an anti-terror crackdown.
Anne Aly, who specialises in counter-terrorism at Curtin University, said there was a growing right-wing, nationalistic movement in Australia which made some Muslims feel like outsiders.
"The jihadist narrative is one that has personally resonated with the everyday lives of some young people in Australia," she told AFP.
"If you look at that narrative, it is all about victimhood, persecution and Muslims under attack."
Canberra has passed a law criminalising travel to terror hot spots and cancelled the passports of over 70 people to prevent them from heading to fight alongside the militants.
But Australian National University visiting professor Clive Williams said: "We need to think about that a bit more strategically. It needs to be a bit more sophisticated than taking away their passport."
The grand mufti of Australia, Ibrahim Abu Mohamed, said in a statement with other Muslim leaders that the community was "devastated" by the turn of events and condemned "this criminal act unequivocally".