action and reaction
A set phrase used in physics, philosophy, or metaphorically to describe opposing forces or responses. Often implies a causal chain where every action provokes a corresponding reaction.
In physics, the law of action and reaction is fundamental.
His criticism was part of the action and reaction against the government's policy.
A compound of 動 (どう, 'motion, action') and 反動 (はんどう, 'reaction, recoil'), linked by と ('and'). The phrase directly expresses the concept of action and reaction.