3-140. Leaders contribute substantially to the unit’s mission success or lack of success. Therefore, the Army devotes considerable resources to foster leader development during exercises. Leader development is an important duty of supervisory leaders and the leader’s chain-of-command. Their responsibility is to provide leaders with accurate observations of their abilities and the effects on unit performance. Providing leadership feedback is a difficult, yet essential, part of training exercises. Without it, the assessment of an important contributor to a unit’s mission accomplishment, namely its leadership, is left undone.