What is Unlawful command influence?

Unlawful command influence is a legal concept within American military law. UCI occurs when a person bearing "the mantle of command authority" uses or appears to use that authority to influence the outcome of military judicial proceedings. Military commanders typically exert significant control over their units, but under the Uniform Code of Military Justice a commander must take a detached, quasi-judicial stance towards certain disciplinary proceedings such as a court-martial. Outside of certain formal actions authorized by the UCMJ, a commander using their authority to influence the outcome of a court-martial commits UCI. If UCI has occurred, the results of a court-martial may be legally challenged and in some cases overturned.