Engineer capabilities are a significant force multiplier in joint operations, facilitating the freedom of action necessary for the joint force commander (JFC) to meet mission objectives. Engineer operations modify, maintain, provide understanding of, and protect the physical environment. Joint doctrine for engineer operations is built upon, and consistent with, the principles of joint operations described in Joint Publication (JP) 1, Doctrine for the Armed Forces of the United States, and JP 3-0, Joint Operations. Engineer operations enhance the ability of the JFC to successfully apply these principles to joint operations.Major operations and campaigns frequently require ground combat (or the possibility of ground combat), as do crisis response and contingency operations. Such operations will require engineers who can integrate their activities with the fires and maneuver of ground combat forces to assure the mobility of friendly forces, alter the mobility of adversaries, and enhance the protection of friendly forces. Some activities require engineer capabilities as an inherent part of a mission to provide support outside the joint force. Engineer support is inherent in the tasks of stability operations to restore or provide essential services, such as water, power, and transportation, and to repair critical infrastructure. This publication provides doctrine for the planning, command and control, execution, and assessment of joint engineer operations. This publication has been prepared under the direction of the Chairman of the Joint Chiefs of Staff. It sets forth joint doctrine to govern the activities and performance of the Armed Forces of the United States in operations and provides the doctrinal basis for interagency coordination and for US military involvement in multinational operations. It provides military guidance for the exercise of authority by combatant commanders and other joint force commanders (JFCs) and prescribes joint doctrine for operations and training. It provides military guidance for use by the Armed Forces in preparing their appropriate plans. It is not the intent of this publication to restrict the authority of the JFC from organizing the force and executing the mission in a manner the JFC deems most appropriate to ensure unity of effort in the accomplishment of the overall objective.