 In 2004 he served as commandant of the Joint Services Command and Staff College, before taking over as deputy commanding general of the Multi-National Corps – Iraq, holding the position from August 2005 to February 2006.Parker was appointed General Officer Commanding Northern Ireland and promoted to the rank of lieutenant-general on 18 July 2006.In Northern Ireland he was responsible for reducing the UK's troop commitment in the Province and is quoted as saying "that the military had made a significant contribution to security in Northern Ireland that has allowed other people to make the difference through politics, social programmes and economics".