Downsizing our army is having a disproportionate effect on African American officers.

The lack of black officers who lead infantry, armor and field artillery battalions and brigades — there are no black colonels at the brigade level this year — threatens the Army's effectiveness, disconnects it from American society and deprives black officers of the principal route to top Army posts, according to officers and military sociologists. Fewer than 10% of the active-duty Army's officers are black compared with 18% of its enlisted men, according to the Army.

The problem is most acute in its main combat units: infantry, armor and artillery. In 2014, there was not a single black colonel among those 25 brigades, the Army's main fighting unit of about 4,000 soldiers. Brigades consist of three to four battalions of 800 to 1,000 soldiers led by lieutenant colonels. Just one of those 78 battalions is scheduled to be led by a black officer in 2015.