established policy; existing procedures; predetermined course
Refers to a course of action, policy, or plan that has already been decided and is being followed. Often used in political, business, or organizational contexts.
The government intends to proceed with reforms according to the established policy.
The proposal was treated as a predetermined course, leaving no room for discussion.
既成事実 refers to a fact that has already been made real and thus hard to reverse, while 既定路線 refers to a course of action already decided in advance, before any fact is created.
Compound of 既定 (already decided) and 路線 (route, line). The term is used metaphorically to refer to a predetermined policy or course of action.