Its independence was secured not only by national legislation within the member states, but also by a treaty between them. Treaties are more binding than national legislation, because they are more difficult to revoke, amend, or repeal.
欧洲央行也许是这一理论的最佳写照。其独立性不仅受成员国国内法律的保护，也受成员国之间所立条约的保护。条约的约束力要高于国内立法，因为条约更加难以取消、修改和废除。