The US Army had difficulty initiating and conducting advisory operations in Operation Iraqi Freedom due to the lack of an institutionalized advisory capability. The need to create an advisory capability after the requirement developed, resulted in a three-year delay in Iraqi Security Force development, which threatened mission success in Iraq. This experience shows that the US Army should consider developing an institutionalized advisory capability. Opponents of this idea view the advisory operation in Iraq as an anomaly and believe that the US Army must remain primarily focused on conventional capabilities. Advocates view the advisory operation in Iraq as an indicator of future requirements and believe that the US Army must have an organization that addresses the challenges of advisory operations. This study utilizes three criteria: importance advisory operations, difficulty developing advisory capability, and frequency of advisory operations to determine if the US Army needs an institutionalized advisory capability. The criteria evaluation utilizes current US Army doctrine and analysis of past advisory operation experiences in Greece, Korea, Vietnam, El Salvador, and Iraq. The analysis shows that US Army doctrine anticipates a frequent and important role for advisory capability in future operations. Analysis of past advisory experiences supports this assessment and identified challenges with developing advisory capability. Based on the anticipated frequent and essential role of advisory operations and the associated developmental difficulties, the US Army should develop an institutionalized advisory capability.