The United States Army Civil Affairs forces are the Department of Defense's primary force specifically trained and educated to shape foreign political-military environments by working through and with host nations, regional partners, and indigenous populations. These forces, and the operations they conduct, are the commander's asset to purposefully engage nonmilitary organizations, institutions, and populations. The U.S. military can expect escalating challenges from ever-increasing operations in complex civil-military environments. Commanders at all levels must pursue integrated whole-of-government approaches to successfully engage the civil dimension of the modern battlefield. As such, CA forces offer unique capabilities that not only enhance the military mission but also ultimately advance U.S. interests. Properly employed CA forces help shape the environment and set the conditions for transition operations. Appendix A provides additional information on transition operations. CAO involve the interaction of CA forces with the civilian populace and institutions to facilitate military operations and consolidate operational objectives. A supportive civilian population can provide resources and information that facilitate friendly operations. It can provide a positive climate for the military and for the nation to pursue diplomatic activities that achieve foreign policy objectives. A hostile civilian population threatens the immediate operations of in-country friendly forces and often undermines public support and the policy objectives of the United States and its allies. Properly executed CAO reduces the friction between the civilian population and the military force, and accelerates the return of civil functions to indigenous control. Field Manual (FM) 3-57, Civil Affairs Operations, provides the doctrinal basis for the conduct of operations in support of the joint force commander's (JFC's) civil-military operations (CMO) concept. It provides Army commanders with the information necessary for the integration of Civil Affairs (CA) capability in support of unified land operations. FM 3-57 clarifies the role of CA forces in support of CMO with regard to the missions, employment, support requirements, capabilities, and limitations of these forces. CA forces support missions in every theater, in peace and war, throughout unified land operations. CA forces are a combat multiplier for every commander. CA forces are one of the primary resources a commander has to assist him in dealing with the complex and ever-changing civil component of the operational environment. CA forces are trained, organized, and equipped to plan, execute, and assess the JFC's concept for CMO. They are essential elements in the support of the commander by virtue of their area and linguistic orientation, cultural awareness, training in military to host nation (HN) advisory activities, and civilian professional skills that parallel common government functions.