Annex II How a State becomes a party to a treaty This annex explains the process by which a State binds itself by the provisions of a treaty in international law as a State party. Further details may be obtained from the United Nations Office of Legal Affairs (http://untreaty. un.org). State party A State party is a State which has agreed to be bound by a treaty under international law. The State must have expressed its consent to be bound by the treaty through an act of ratification, acceptance, approval or accession, and the date of entry into force of the treaty for that particular State must have passed. Some treaties, such as the human rights treaties described in this Fact Sheet, are open only to States, whereas others are also open to other entities with treaty-making capacity. Both Covenants and the International Convention on the Elimination of All Forms of Racial Discrimination are open to signature and ratification by "any State Member of the United Nations or member of any of its specialized agencies, by any State Party to the Statute of the International Court of Justice, and by any other State which has been invited by the General Assembly of the United Nations". The other core human rights treaties are open to all States. The optional protocols are all restricted to the State parties to the parent treaty, except the Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict, to which any State may accede. How does a State become a party to a treaty? Each human rights treaty contains provisions setting out, first, how States must proceed to bind themselves by the substantive provisions of the treaty and, second, when the treaty will enter into force. In order to become a party to a multilateral treaty, a State must demonstrate, through a concrete act, its willingness to abide by the legal rights and obligations contained in the treaty. In other words, it must express its consent to be bound by it. In accordance with the final clauses of the relevant treaty, a State can do this either through signature followed by ratification, accep­ tance or approval, or through accession. Under certain circumstances, a State may also bind itself through succession. Many treaties require a minimum number of State parties before they can enter into force in international law. 58