Antonyms for the phrase "were brought about" are "were prevented," "were halted," "were obstructed," "were hindered," "were impeded," and "were curtailed." These words indicate the opposite of "were brought about," which means that something was initiated, caused, or brought into being. When something is prevented, halted, or obstructed, it means that it is not allowed to happen or is stopped before it can begin. Similarly, when something is hindered, impeded, or curtailed, it is slowed down or limited in some way. To use these antonyms effectively in writing, it is important to understand their meanings and context.