Which manual focuses on the Tactical Employment of Mortars?

The focus on the Tactical Employment of Mortars is specifically addressed in ATP 3-21.90. This manual provides comprehensive guidelines and strategies for integrating mortars into infantry operations and emphasizes their tactical use on the battlefield. It covers various aspects of mortar operations, such as fire support coordination, deployment tactics, and the roles mortars play in combined arms operations.

In contrast, the other manuals mentioned may cover different aspects of military tactics, training, or procedures, but they do not focus specifically on the tactical employment of mortars. For instance, TC 3-21.90 primarily deals with training and tactics for infantry formations, while FM 3-90.1 and ATP 3-90.1 focus more broadly on maneuver operations rather than the specialized tactical applications of mortars. Thus, ATP 3-21.90 is the definitive resource for understanding how to effectively employ mortars in tactical situations.