was commissioned a lieutenant on 11 December 1968. He was allotted to the Royal Australian Infantry. He arrived in South Vietnam on 3 August 1969 and was posted to 9th Battalion, Royal Australian Regiment on 20 August 1969. On 10 October 1969, Lieutenant Cosgrove was commanding 5 Platoon, B Company. The platoon located an occupied bunker system in an area where, because of the proximity of allied troops, indirect fire support was difficult to obtain. In spite of this, he led his platoon in an assault on the bunkers without indirect fire support, capturing the system and killing and wounding at least four enemy without sustaining any casualties. On 16 October 1969, 5 Platoon located another bunker system occupied by about a platoon of enemy. Lieutenant Cosgrove silently deployed his own platoon for an attack. His assault completely surprised the enemy causing them to flee, abandoning large quantities of food, stores and documents. The following day in the same bunker system a party of enemy approached his right forward section and was engaged by the sentry. Knowing that the remainder of the section was elsewhere on other tasks, Lieutenant Cosgrove ran to the contact area and personally conducted the fight against the enemy. As a result of his actions, two enemy were killed and three weapons and four packs containing rice were captured. He was awarded the Military Cross for these actions. Cosgrove was promoted to the temporary rank of captain on 21 September 1970, and was appointed an aide-de-camp to the then-Governor-General Paul Hasluck on 20 December 1971. He was promoted to substantive captain on 31 October 1974 (seniority from 13 July), to temporary major on 2 January 1976 and to substantive major on 11 December 1978. In 1980 he was awarded the National Medal, and was promoted to lieutenant-colonel on 7 December 1981. In the mid-1980s he commanded the 1st Battalion, Royal Australian Regiment. Cosgrove came to national fame in 1999 when, as a major general, he led the international forces (INTERFET) in a peacekeeping mission to East Timor. The mission's success made him one of Australia's most respected and popular military leaders. He returned to Australia in 2000 as Land Commander Australia, was promoted to lieutenant general in July and appointed Chief of the Army and, in 2002, was advanced to general as Chief of the Defence Force. In 2004, the Foreign Minister Alexander Downer queried the