RETALIATION comes in MANY forms, & not necessarily war, such as economic lost opportunities, legal means to force authorities to follow Rule of law, etc, etc. Thus make NO mistakes that Australia did not retaliate.
ULTIMATELY, when dealing with barbarians whom only understand the lingo of violence, the irony of PEACE is that it MUST be defended by arms & sacrifices.
Mistakes made by liberal but naive minded Humanity had ALLOWED terrorists & criminals to take advantage of our democratic systems to flourish in our World.
It is time to strike back, to save Humankind.....