The phrase "chain of circumstances" refers to a series of events or situations that are related to each other and lead to a particular outcome. Synonyms for this phrase may include "sequence of events," "cause and effect chain," "domino effect," "cascade of events," "long train of events," or "thread of circumstances." All of these phrases capture the idea of events unfolding in a connected way, leading to a specific result. When discussing a complex situation or trying to trace the root causes of a problem, using these synonyms can help to add depth and complexity to analysis and understanding of the situation.