When applying the principle of mass, where should combat power be concentrated?

• A. At the decisive point.
• B. Along the entire front.
• C. In reserves only.
• D. In rear areas to protect supply lines.

Answer: (A)

Mass means concentrating combat power where it will produce the greatest effect—the decisive point—at the right time. When you funnel the main effort there, you generate overwhelming force and tempo, overwhelming the enemy's ability to respond and securing a rapid, favorable outcome. The idea is to deliver enough firepower, maneuver, and momentum in a single, coordinated push to break through and achieve the objective with minimal delay.

Spreading forces along the entire front dilutes impact and gives the enemy room to absorb pressure and reorganize. Keeping everything in reserve delays action and can cause you to miss the critical window when the decisive point is open. Focusing on rear areas to protect supply lines diverts combat power away from the moment when striking power is most needed, weakening the chances of a breakthrough at the point of decision.

A concrete sense of this is applying the main effort to a vulnerability or juncture in the enemy’s line where success would disrupt their command and advance, then exploiting that breach with follow-on forces. That concentrated, well-timed action is what delivers decisive results.