From January to August 2000, Cross attended the Royal College of Defence Studies, after which he was promoted to major general (two-star rank) and appointed Director General, Defence Supply Chain. While Director General, he was responsible for the establishment of the United Kingdom's Joint Force Logistic Component for the forthcoming operations in Iraq and became involved in planning for the invasion of the country. In early 2003, he became the British representative to the United States Department of Defense's Office for Reconstruction and Humanitarian Assistance, later the Coalition Provisional Authority following the invasion, and one of three deputies to American Lieutenant General Jay Garner.