After the discussion of the powers of the Security Council in the previous chapter, this chapter considers some of the limitations on these powers, real or imagined. In particular, it examines limits deriving from the Purposes and Principles of the United Nations and the norms of jus cogens. Then, it explores some checks and balances on the actions of the Council. Ultimately, our response is that states do not have the right to do this, and would be acting unlawfully if they purported to exercise such a right. But they do, of course, have the ultimate option as a matter of policy of simply disregarding binding obligations imposed by the Council, with all the consequences, political and legal, that might flow from such a course of action. That is why the Council needs to exercise self-restraint and use its undoubted powers responsibly and only where it really is necessary to do so in order to ensure prompt and effective action to maintain international peace and security. This is the most effective check on the Council’s power.