Gen. Chiarelli dedicated 40 years of his career to creating and implementing American defense policy for the US Army and Department of Defense (DoD).
He served in a multitude of positions, including vice chief of staff, Army; senior military assistant for the Secretary of Defense, The Honorable Robert Gates during the surge of forces into Iraq (2007–2008); multi-national corps commander in Iraq (2006); division commander in Iraq (2004–2005); chief of the Army Operations Center in the Pentagon during the attacks on September 11, 2001, and for the 2 years following that included the preparation for and commencement of the Afghanistan and Iraq campaigns (2011–2013);
executive officer for the Supreme Allied Commander Europe/EUCOM Commander General Wesley Clark during the Kosovo Air War (1998–2000); assistant professor and head of counseling for the Department of Social Sciences, United States Military Academy (1980–1984); and commander at all levels from an Army Platoon (50 soldiers) to a Multi-National Corps in Iraq (140,000 soldiers) (1972–2006).
After retiring from the military, Gen. Chiarelli became the Chief Executive Officer of One Mind, a 501(c)(3) focused on finding better diagnostics and treatments for those suffering from a variety of brain-related ailments, including mental illness, addiction, post-traumatic stress, and traumatic brain injury. At One Mind, he was dedicated to fostering fundamental changes to radically accelerate the development and implementation of improved diagnostics, treatments, and cures for diseases and injuries of the brain—all while eliminating the stigma and discrimination that those affected may experience. He left that position in mid-January 2018. He remains a One Mind ambassador.