Australian troops could be out of Afghanistan as early as 2013 under a timeline which sees training of the Afghan National Army continuing for up to four years, followed by a period of security backup of the fledgling force.
In a week when three Australian soldiers died in a helicopter crash - taking the Australian death toll in the nine-year war to 16 - Defence Minister John Faulkner warned more losses could be ahead.
"But we must stay the course," he said.
In a major development for Australia's mission in Afghanistan, the government announced the United States would replace The Netherlands as lead nation in Oruzgan province in southern Afghanistan.
Australia has 1550 troops in Afghanistan, most of them in Oruzgan province where they have operated under overall Dutch control since 2006.
Senator Faulkner said new arrangements for military and civilian operations in Oruzgan were needed because of the impending withdrawal of Dutch forces from August.
Under these new arrangements, the US will head a multinational Combined Team Oruzgan comprising US, Australian, Slovak and Singaporean forces.
However, the US has yet to say just what forces it will deploy into Oruzgan to replace outgoing Dutch units, in particular artillery and a field hospital at the Tarin Kowt base.
Senator Faulkner said the Dutch role would be more than adequately filled by the new Combined Team Oruzgan.
He said Australia would take on a new responsibility by providing a civilian to head the Oruzgan Provincial Reconstruction Team, a position previously held by the Dutch.
Australia would also take on an increased role in security for Australian civilian aid activity in the province.
He said Australia's operational objective in Afghanistan was to train the Afghan National Army (ANA) 4th Brigade to the point where it was able to take responsibility for security and stability in Oruzgan province.
"CDF (defence force head Angus Houston) has advised me that on the basis of our solid progress to date, defence now estimates that within two to four years we will be able to transition the main security responsibility to the ANA," he said.
Senator Faulkner said he would expect, on completion of training, some troops would withdraw with others staying in an overwatch role, providing security backup for Afghan forces.
That's what happened in Iraq, with Australian troops acting in this role for a year before withdrawing.
On that basis, Australia's mission could end as early as 2013 or as late as 2015.
Senator Faulkner said he deliberately wasn't setting a timeframe.
"I haven't been provided with a precise timeframe from the ADF for very good reasons.
"This depends on a number of factors, not the least the conditions on the ground ... and the role played by our partners in the new Combined Team Oruzgan."
Senator Faulkner said Australia's fundamental objective in Afghanistan was to ensure it didn't again become a safe haven for terrorists linked to attacks on Australians in Bali in 2002.
Despite setbacks, there had been progress, he said.
In Oruzgan, there had been considerable success in disrupting insurgent networks and extending government influence to previously insurgent-controlled areas.
"As we bring the fight to the Taliban in more parts of the country, this will lead to more incidents. But we are making headway," he said.
Subject: Australia could quit Afghanistan in 3yrs 
June 23rd 2010, 1:08 pm