As the state is the only legal personality authorized to enter into a treaty and make international law, the state bears a legally binding duty (obligation) either to act positively or refrain from acting negatively so as to uphold the terms of the treaty or other norm of international law. In human rights law, to every right correspond obligations of the state as the primary duty holder. Consistent with its ratification of international human rights treaties, the State Party must “take steps, individually and through international assistance and cooperation…to the maximum of its available resources, with a view to achieving progressively the full realization of the rights recognized…by all appropriate means, including particularly the adoption of legislative measures. Thus, the State also guarantees “that the rights…will be exercised without discrimination of any kind as to race, colour, sex, language, religion, political or other opinion, national or social origin, property, birth or other status.” Likewise, the state is obliged to meet its obligations by ensuring gender equality.
A State’s human rights obligation is comprised of three aspects: (1) to respect, (2) to protect and (3) to fulfill the right. The obligation to respect requires States to refrain from interfering with the enjoyment of the right. (Thus, the State fulfills its duty to respect the right to housing when it refrains from arbitrary forced evictions or other outright violation.) The obligation to protect requires States to prevent violations of such rights by other (third) parties. (Thus, the State discharges its obligation to protect the human right to adequate housing when it prevents private developers from carrying out forced evictions and/or prosecutes those responsible for the violation; or the State meets its obligations to protect inhabitants’ housing rights by treating domestic violence as a crime.) The obligation to fulfill requires States to take appropriate legislative, administrative, budgetary, judicial and other measures toward the full realization of the right. Therefore, when the State increases the amount or proportion of its budget for participatory slum upgrading through domestic or overseas development assistance, it is acting in compliance with its treaty-bound obligation by applying the over-riding principle of ensuring the maximum of available resources to fulfill the right to adequate housing.
“Obligation” is a term usually reserved for a state’s agreed-upon, ratified and required preventive or remedial actions that are specifically treaty-based. Compliance with an “obligation” is binding and, thus, subject to various forms of adjudication. Grounding a claim in an “obligation” implies that the state bears a duty arising from a treaty, or a general principle of customary law that is also theoretically subject to adjudication.
“Obligation” is the strongest and most “black-letter law”-based of the three terms (commitment, responsibility and obligation) evoking duty and liability of the state.
 International Covenant on Economic, Social and Cultural Rights (ICESCR), Article 2.
 Maastricht Guidelines on Violations of Economic, Social and Cultural Rights, Maastricht, 22–26 January 1997.