Mr Abbott said the number of Australians estimated to be fighting with Islamic State in Iraq and Syria was a major factor behind his government's decision to deploy the military and reiterated his warning to Australian Muslims flirting with the idea of travelling to join in the fight that they should stay at home. Prime Minister Tony Abbott hit the airwaves on Monday morning to explain his decision to commit 600 Australians to take part in action to destroy the Islamic State. Credit:Alex Ellinghausen "It is very dangerous, it is wrong, it is against God, it is against religion, it is against our common humanity, as Prime Minister Najib of Malaysia said just the other day, and it may well become much more dangerous because of the presence of Australian forces" he told reporters in the Northern Territory. The government said it would be "artificial and impossible" to specifiy a time frame for the mission, but Mr Abbott stressed the"specific objective" is to drive ISIL "entirely from Iraq". "We're not trying to create a liberal pluralist democracy, we're not trying to create a shining city on the hill," the Prime Minister told the ABC.

"If the Iraqi government, the Kurdish regional government are able to maintain reasonable control over their substantial towns, if they're able to provide reasonable protection to their own people that will be success." US President Barack Obama has vowed to also attack Islamic State across the Iraqi border in Syria but Mr Abbott said Australia had no intention joining such a mission as it would mean operating without the permission of the Syrian regime, unlike in Iraq where the government has requested Western help. Mr Abbott praised Mr Obama's response to the threat posted by Islamic State, also known as ISIL, which he said had been "calm" and "measured". "President Obama, as you know, has not been quick to reach for the gun here," he told the Seven Network.

Mr Abbott again prepared voters for the mission to stretch on for more than just a few months - "this is not the task of weeks or even necessarily, just a few months".

Attorney-General George Brandis said the mission would take an "unspecified and potentially quite long period of time" and noted that ASIO raised the terror alert to "high" on Friday "with no foreknowledge of" the National Security Committee's decision to deploy forces to the Middle East, rejecting the Greens claim that it would further expose Australia to a terrorist attack. He hit out at Greens leader Christine Milne and called her "simple minded" and "ignorant" for drawing links between the current mission and the Iraq War that began just over 10 years ago. "The suggestion that comes from simple minded people like Senator Milne that this is like 2003 when there was actually an invasion with the advertent purpose of regime change couldn't be more wrong," he told the ABC. Mission not war Speaking a short time later on Sky, the Attorney-General denied the cabinet's decision means Australia was once more at war in Iraq.

"I don't think it's correct to describe what we are speaking of as a war, it is a mission, it is essentially a humanitarian mission with military elements of course," he said. Treasurer Joe Hockey would not put a figure on Monday to the hit the federal budget would take to fund Australia's military involvement in Iraq. Mr Hockey said, ultimately, "you can't put a price on doing what is right". He said the defence budget could absorb "a significant amount of these sorts of costs" but beyond that the government would have to look elsewhere in the budget to pay for Australia's part in a coalition of nations led by the US. The Treasurer said the costs would be evident in the mid-year economic and fiscal outlook later this year.

"Defence has the capacity to absorb a significant amount of these sorts of costs but after that it does come out of the rest of the budget," Mr Hockey said. "But ultimately you can't put a price on protecting human beings and that's what we're doing." Mr Hockey added that Australia had a responsibility to "step up to the plate for humanitarian reasons but also in the defence of our nation". "Because their tentacles reach into our communities and we've got to sever those tentacles and it's best to sever them at the base of where ISIL is at its meanest and worst," he said. Labor is supporting the government's action.

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