The phrase "plan attack" can be substituted with a multitude of synonyms to convey different levels of aggression or strategic planning. For instance, "plot assault" suggests a more violent and deliberate intent while "scheme raid" implies a more secretive and strategic approach. Other options include "devise strike," "organize aggression," "formulate offensive," and "prepare offensive action." Additionally, using synonyms like "craft strategy" or "develop plan" can broaden the scope of the action to include non-violent or non-physical methods of attack such as political maneuvers, cyberattacks, or economic sanctions. Overall, selecting the appropriate synonym depends on the context and intent of the action being described.