Abstract American military forces have been working on a major doctrinal change since the middle of the last decade to move away from counterinsurgency and toward large-scale conventional warfare. The introduction of the concept of Multi-Dimensional Operations ( MDO ) to fight peer competitors has been accompanied by extensive historical studies of previous conventional campaigns. This article looks at the lessons learned from one of the main recent collections of historical cases, the Army’s Large-Scale Combat Operations ( LSCO ) Series. The book series contains a large number of cases of major conventional war from the twentieth and twenty-first centuries, and demonstrates a clear break with doctrine and historical interpretation developed in Iraq and in Afghanistan. Two sets of historical cases from the LSCO series were chosen for this study, the analyses of the October 1973 War and of the Soviet experience in World War II . These were also two of the main cases that were used in the 1970s and 1980s to help develop AirLand Battle doctrine after Vietnam. The article examines the lessons learned from both of the cases in the LSCO Series and compares those to earlier lessons learned about the same cases in the 1970s and 1980s. In this way, it also finds that the U.S. Army believes that AirLand Battle doctrine continues to be relevant today from a historical standpoint of lessons learned.