Former elite soldier from Sydney's 2 Commando Regiment Paul Cale experienced five combat deployments before leaving the Army, including two missions to Afghanistan and one to Iraq.
He said the only way to defeat Islamic State is to send in ground troops, as soon as possible.
"You cannot control the war from the air," he said. "ISIS is a threat to the entire region and there's a domestic threat to Australia as well and the longer it's allowed to go on with impunity the greater the confidence ISIS will have and the more foreign fighters will join them."
Mr Cale said that going back to Iraq is the right thing to do, morally.
"These countries are full of moderate Muslims who want their girls to have an education, they want the best for their families and they want economic development.
"The extremists are there to stop them and because these countries don't have good internal security they cannot stop ISIS.
"Here in Australia we have very sophisticated internal security to deal the threat of ISIS - over there they don't have that. This is about people beheading children just because they are not Muslim or not the right kind of Muslim."
Mr Cale said Australia should have become involved in the conflict with ISIS sooner but he understood the government's reluctance to go back to Iraq.
"We got out of the war in Iraq and whatever the political motivation for the initial war, this is totally different," he said.
"I am impressed to see Australia going into air support and now bombing, we are not just standing back."
Mr Cale said Australia should send its special forces into ground combat.
"We have made substantial investment in our special forces capabilities," he said.
"The 2 Commando Regiment has been able to alleviate the massive workload on the SAS. Our special forces capabilities are world class and they have a lot of flexibility.
"This is their profession, they are highly trained, highly disciplined."
Mr Cale said there would be negative consequences for Australia if ISIS was not stopped.
"Because of what is happening now a lot of people fear Islam," he said.
"I fear that further down the track the consequences of the extremist actions of radicals and jihadists will be very bad for Islam because eventually the pendulum will swing back so far the other way that we will have extremists on the other side.
"It will be a horrible situation for Islamic communities who will become persecuted. It's hard to see that right now, but that's my prediction if ISIS is not stopped immediately ... it would be very dangerous for a fair and open democracy like Australia."
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