Callender joined the Australian Army in 1996 as a Rifleman in the
6th Battalion, The Royal Australian Regiment. He graduated from the
Royal Military College, Duntroon in 2001 to the
Royal Australian Armoured Corps. His operational experience includes two deployments as part of the
Australian Security Detachment – Baghdad; the first as a Cavalry Troop Leader in 2004, and the second as an Executive Officer in 2006. In 2004, as junior cavalry officer in the
Australian Army, he was deployed to
Iraq. Garth became Australia's first serious casualty in the war when his patrol was targeted in a roadside bomb attack. After recovering from his injuries, Callender returned to Iraq in 2006 as second-in-command of the Australian Army's security detachment in Baghdad. His combat team suffered the death one of their own, Private
Jake Kovco. Over June 2009 to February 2010, Callender commanded the Weapons Intelligence Team in
Uruzgan Province,
Afghanistan. His team was successful as the first team to develop
technical intelligence products to focus coalition intelligence collection, planning and operations. These reports proved pivotal in shaping the
Australian Government’s understanding of incidents involving Australian casualties and defining policy regarding Australia’s commitment to
Afghanistan. He remains an active member of the
Army Reserve. == After the Blast ==