Shortly after the Islamist inspired terrorist attacks in New York and Washington on 11 September 2001 , Australian forces were committed to the American @-@ led international coalition against terrorism . The ADF 's most visible contribution — codenamed Operation Slipper — has been a special forces task group operating in Afghanistan from 2001 to 2002 and again from mid @-@ 2005 to fight against the Taliban . Over time the Australian commitment has grown , with the addition of further ground forces in the form of a Reconstruction Task Force from 2006 to provide security , reconstruction and to mentor and train the Afghan National Army . Australia has also contributed a frigate and two AP @-@ 3C Orion surveillance aircraft and three C @-@ 130 Hercules transport aircraft to international operations in the Persian Gulf and Indian Ocean since 2001 , supporting both the operations in Afghanistan and those in Iraq under Operation Catalyst . A detachment of four F / A @-@ 18 Hornet fighter @-@ bombers was based at Diego Garcia from late @-@ 2001 to mid @-@ 2002 , while two Boeing 707 air @-@ to @-@ air refuelling aircraft were also based in Manas Air Base in Kyrgyzstan to provide support to coalition aircraft operating in Afghan airspace but were later withdrawn . A Special Operations Task Group was deployed to support the Reconstruction Taskforce in April 2007 . In addition to radar crews , logistics and intelligence officers , and security personnel , this brought the number of Australian personnel in Afghanistan to 950 by mid @-@ 2007 , with further small increases to 1 @,@ 000 in mid @-@ 2008 , 1 @,@ 100 in early 2009 and 1 @,@ 550 in mid @-@ 2009 .