The phrase "breaking one up" implies the act of separating or dismantling something. Antonyms for this term would be "assembling," "building up," and "consolidating." These words denote the creation or combination of something, rather than the act of taking it apart. Other antonyms may include "uniting," "joining," and "integrating," which all refer to the process of bringing separate elements together. These antonyms suggest a sense of positivity and progress, rather than a sense of destruction or dissolution. While "breaking one up" may be necessary in some contexts, it is always valuable to consider alternative actions that promote cooperation and collaboration.