Dean joined the DCNG in 1985. His first assignment as a commander came in 1989, with the 274th Military Police company. In the earlier part of 1991, the DCNG was mobilized along with other National Guard units in order to participate in the Persian gulf conflict. Captain (CPT) Dean, during that time period, along with other unit commanders within the DCNG, prepared many troops to participate in the battle to liberate Kuwait. This conflict occurred due to Iraq's refusal to respond to the United Nations (UN) deadline.