Peter enlisted in the Army as a soldier in 1980, and in 1990 he graduated first in class and Queens Medallist from the Royal Military College Duntroon. He has a Bachelors Degree in Professional Studies (Management) from the University of New England and a Master of Arts in Defence Studies with the Canberra University.

Peter served 17 of his 25 years in the Army with the Special Air Service Regiment. He held appointments from Trooper to Chief Operations Officer and commanded at every level from a patrol of six to an SAS Sabre Squadron. He has the honour of being the first member in the history of the SAS to advance from Trooper to Squadron Commander of a sabre squadron.

During this time, Peter participated and commanded an extensive number of operations globally culminating in his final appointment as the SAS Chief Operations Officer from 2001 to 2004. This final period was an unprecedented period of operations for the SAS from peace and security on Bougainville to high-intensity conventional warfare in Iraq. As the principal planner, Peter developed and executed plans for operations worldwide including East Timor, Christmas Island (Tampa), Afghanistan and Iraq. He was the lead tactical planner for Australia's Special Forces contribution to both the Afghanistan and Iraq campaigns. In these later operations, he was appointed as the Deputy Commander of the Joint Special Forces Task Group.

In the execution of these plans, Peter has amassed a range of unique experiences for planning and managing in dynamic high-risk cross-cultural environments to achieve national objectives. His principal skills are in the areas of strategy and leadership. Peter's other personal operational experiences include secondments to the United Nations Truce Supervision Organisation (UNTSO) in the Middle East where he saw tours of duty in Southern Lebanon and on the Syrian side of the Golan Heights and two operations in Bougainville, PNG.

In 2003, Peter's service was recognised with his appointment as a Member of the Order of Australia (AM), specifically for, '...exceptional performance of duty, particularly in the development of outstanding mission concepts and operational plans, in warlike operations...'.

On his departure from the SAS, Peter developed a boutique consultation business in leadership and team building servicing a niche demand in corporate Australia using a practical "front of lectern" style. Concurrently Peter established a small manufacturing business producing building products for the WA and NSW markets using Western Australian limestone.

Following the sale of these businesses in 2007, Peter established a mine camp operations business servicing the resource sector in the Pilbara. And in February 2009 Peter established an investment management business with the mandate to acquire and develop assets in the North West and Kimberley regions of Western Australia for the provision of accommodation and services to the tourism and resource sectors.

In 2009 Peter stepped down from his business interests to re-enter public service as a member of the Western Australian Parliament, following a successful by-election campaign, and was sworn in as the Member for Willagee on the 10 February 2010. During 2012, Peter was WA Labor's Shadow Minister for Planning, Housing, and Local Jobs.

After being re-elected in early 2013, Peter was elected President of the State Labor Caucus and in mid-2014 was elected by a popular vote of members as the President of WA Labor for a two-year term. In July of 2015, Peter was appointed to the Shadow Cabinet as Shadow Minister for Asian Engagement, Trade, Science and Lands.