The phrase "were operation" can be replaced by several synonyms depending on the context. For example, we can use the word surgery, which refers to a medical operation performed on a patient to treat a physical injury or ailment. Another phrase that can be used as a synonym in the context of military operations is "were campaign," which refers to a series of planned military actions that aim to achieve a specific objective. "Were procedure" can also be used to refer to a routine or standard operating procedure that is followed to execute a particular action or task. Other possible synonyms for "were operation" include activities, maneuvers, and exercises, amongst others, depending on the context in which they are used.