powder keg

The phrase "powder keg" generally refers to a situation or place that is highly volatile, unstable, and likely to explode or become violent. It is often used metaphorically to describe a situation where tension and conflict are present, and any small spark or incident could trigger a major, potentially disastrous escalation. The term originates from the practice of storing gunpowder in kegs, which are highly flammable and could cause a catastrophic explosion if mishandled or ignited.