This monograph seeks to determine what implications for crisis action planning and operational art in combined environments can be derived from the German experience in the invasion of Yugoslavia (April 1941). This study has two collateral functions. First, from an historical standpoint, it highlights the state of German operational art between campaigns in France and Russia. Second, it provides a concise summary of the German invasion for military professionals currently exploring the history of warfare in Yugoslavia. On 27 March 1941, Adolf Hitler informed key political and military leaders of Nazi Germany that he had decided to invade Yugoslavia at the earliest possible moment. Prior to that meeting, the Wehrmacht was preparing for the invasions of Greece and Russia, and had no plans for an attack on Yugoslavia. However, by 5 April they had developed a campaign plan -- OPERATION 25-- and staged 21 divisions in Austria and three allied nations for the invasion. Furthermore, they coordinated their operation with four allied nations, two of whom join in the attack. OPERATION 25 began on 6 April and on the 18th Yugoslavia capitulated. The campaign moved from concept to termination in 23 days. Despite weak Yugoslav opposition, the German feat of arms was a remarkably successful example of crisis response and operational art in a combined environment. An analysis of OPERATION 25 offers valuable insights for the U.S. military today. The focus of this monograph is limited to crisis action procedures involving the commitment of military force. It is further limited to operational art in a combined environment. Specifically, the monograph compares the German reaction to the Yugoslav crisis in 1941 with the six "Time Sensitive Planning Phases" described in Joint Publication 5-02.4, Joint Operation Planning System, Volume IV, Crisis Action Procedures (JOPS Volume IV). It identifies significant differences and similarities that have implications for U.S. doctrine. The monograph applies the same approach to the characteristics of operational art found in Field Manual 100-5, Operations. Here the study examines the relationship between military means and political ends; the integration of tactics, operations and strategy to achieve political ends; centers of gravity; and the sequence of the campaign. Combined operations are addressed when they impact on crisis action planning and operational art. The monograph concludes that the German reaction to the Yugoslav crisis was similar to current U.S. doctrine for crisis action. The same is true for the U.S. Army's concept of operational art. Implications drawn from the study indicate a need to include guidelines for combined operations, conflict termination and postconflict operations in crisis action procedures. Likewise, current doctrine for combined operations should address time sensitive planning in a combined environment. Finally, this analysis of OPERATION 25, supports current doctrine by providing an historical precedent where similar methodologies were successfully employed.

ADA 274043 Approved for public release; Distribution is unlimited. The opinions and conclusions expressed herein are those of the student-authors and do not necessarily represent the views of the U.S. Army Command and General Staff College or any other governmental agency. (References to these studies should include the foregoing statement.)