On return to Australia in 1953 he became Adjt 1 PIR in PNG. In 1954 he was Adjt with 16 Inf Bn (CMF) and in 1956 Staff Capt A in HQ W Comd Then in 1957–58 he served in the United Kingdom with the Royal Marine Commandos and saw duty in Malta, and operational service in Cyprus. He then served as OC 2 Cdo Coy from Jul 1957 to Jun 1961, and after attending the Australian Staff College, became the Senior, then Chief Instructor at OCS, Portsea from 1962 to 1965. He was then posted until 10 July 1967 to Army HQ which had moved to Canberra in the early 1960s from Melbourne.
He then commanded the 1st Battalion and for service in Vietnam in 1968–69 and was awarded the Distinguished Service Order. On return from UK Joint service training in 1971 he became Colonel Coordination in the office of CGS and in Apr 1974 became Brigadier, Chief of Staff at HQ Field Force Command in Sydney until Dec 1975.
He attended senior officer training at the Australian Staff College first long course in 1960–61, Joint Services Staff College in UK as a student then exchange instructor 1969–71, and then the Royal College of Defence Studies in UK in 1976.
He commanded the 1st Division 1977–79, became Assistant Chief of Defence Staff 1979–82, Chief of the General Staff 1982–84 and (the first) Chief of the Australian Defence Force in 1984 (the position having been changed from Chief of the Defence Staff). He retired from the Army in April 1987.
Sir Phillip on several occasions also became Administrator of the Commonwealth during overseas visits by the Governor-General, acting for the then Governor General of Australia the Hon. William George Hayden AC.
In 1983 he received the US Legion of Merit (Degree of Commander) and in 1985 the Republic of Korea Order of National Security Medal. He was made an Honorary LLD (NSW) in Oct 1995 for his contribution to military education and the Australian Defence Force Academy. He was made a Knight of St John in 1988 and awarded the degree of Doctor of Laws, honoris causa, by the University of Tasmania in 1992. He was awarded the Centenary Medal in 2001.
|Companion of the Order of Australia (AC)||(1985)|
|Officer of the Order of Australia (OA)||(1981)|
|Knight Commander of the Order of the British Empire (KBE)||(1982)|
|Distinguished Service Order (DSO)||(1969)|
|Knight of the Most Venerable Order of St John (KStJ)||(1988)|
|Australian Active Service Medal 1945-1975|
|Korea Medal with Bronze Oakleaf for Mentioned in Dispatches|
|United Nations Korea Medal|
|General Service Medal (With Malaya clasp)|
|Australian Service Medal 1945-1975|
|Defence Force Service Medal (with Federation Star)||(40-45 years service)|
|National Medal with first clasp||(1977)|
|Australian Defence Medal|
|Vietnam Campaign Medal (Republic of Vietnam)|
|Commander of the US Legion of Merit (United States of America)||(1983)|
|Order of National Security Merit (Tong-il Medal) (South Korea)||(1985)|