Final answer:
The vital ingredient of the Army's strength and effectiveness is military capacity, which includes factors such as training, equipment, strategy, and leadership.
Step-by-step explanation:
The vital ingredient of the Army's strength and effectiveness is military capacity. Military capacity refers to the ability of a military force to fight and achieve its objectives. It includes factors such as training, equipment, strategy, and leadership. For example, a well-trained and equipped army with effective leadership and strategic planning will have a higher military capacity and therefore greater strength and effectiveness.