The United Nations Human Rights System 1 Some of the treaties have been supplemented by Optional Protocols, which address specific human rights issues or establish new procedures, except for the Optional Protocol to the Convention against Torture establishing a committee of experts (see Table 1). The international human rights treaties are complemented by other human rights instruments such as declarations, guidelines and principles adopted at international level which contribute to the understanding, implementation and development of human rights. Please refer to Annex 1, for a nonexhaustive selection of these instruments. States can become parties to treaties, including human rights treaties, through signature and ratification (a two-step process) or accession (a one-step process). Both ratification and accession should be followed by the depositing of an instrument of ratification or accession with the SecretaryGeneral of the United Nations (the depository) in accordance with the final clauses of the respective treaty. Becoming a State party to human rights treaties deposited with the Secretary-General Signature is a legal act expressing a will to become a State party to the treaty in the future. It is always subject to ratification in the case of human rights treaties deposited with the SecretaryGeneral. The signatory State is not yet a State party and is therefore not bound by the treaty. The only legal obligation of the signatory State is to refrain, in good faith, from acts that would defeat the object or purpose of the treaty. The act of signature qualifies the signatory State to continue with the ratification. However, signature does not create an obligation to ratify the treaty. Ratification is a legal act expressing the State’s will to be bound by the treaty. Ratification at international level should be distinguished from domestic ratification which is the domestic process for approving a treaty. Domestic ratification gives a signatory State time to seek the required approval for the treaty in accordance with its constitutional procedures, and to enact the necessary legislation to give the treaty effect at national level. Ratification at international level is effected by the deposit of an instrument of ratification with the Secretary-General of the United Nations. Accession has the same legal effect as ratification at international level, but does not require prior signature of the treaty in question. Accession is effected by the deposit of an instrument of accession with the Secretary-General of the United Nations. *Since the adoption of the UDHR in 1948, all UN Member States have ratified at least two core international human rights treaties, and 80% have ratified four or more. By becoming parties to human rights treaties, States assume obligations and duties under international law which entail the threefold responsibility to respect, protect and fulfil the human rights enshrined in those treaties. The obligation to respect means that State parties must refrain from interfering with or curtailing the enjoyment of human rights. The obligation to protect requires State parties to protect individuals and groups against human rights abuses. The obligation to fulfil means that State parties must take positive action to facilitate the enjoyment of human rights. Concerning the right to life, for example, the obligation to respect requires that State security forces never summarily execute individuals; the obligation to protect obliges a State to investigate any killing and to prosecute perpetrators; and the obligation to fulfil necessitates taking measures to prevent maternal mortality. 5