If you are looking for the "official" term, based on jargon as seen in US War College usage...the general term is:
deception operation
From the Bibliography of the same name written by Dr. Gary J. Byorge, and published by U. S Army Command and General Staff College (1986)
The paper describes a number of operations that were designed to distract the enemy throughout the history of modern warfare. A famous example includes the ruse called Operation Mincemeat, also known as The Man who Never Was.
…and his detailed description of these events gives a special insight into how deception operations are planned and implemented. The analysis of German reactions to the deception presents useful lessons in the psychology of deception. This deception operation, which caused the Germans to redeploy…