Nuclear-free zone
A nuclear-weapon-free zone (NWFZ) is a delineated geographic region where participating states commit via treaty to abstain from the manufacture, acquisition, testing, possession, or deployment of nuclear weapons, aiming to foster regional security without reliance on nuclear deterrence.[1][2] These zones typically incorporate verification mechanisms, such as safeguards administered by the International Atomic Energy Agency (IAEA), and may extend prohibitions to nuclear-armed states through optional protocols promising non-use or non-threat of nuclear weapons against zone members.[1][3] The concept emerged amid Cold War tensions, with the inaugural treaty, the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean (Treaty of Tlatelolco), signed in 1967 and entering force in 1969, marking the first such denuclearization of a densely populated area and covering 33 states from Mexico to Argentina, including surrounding maritime zones.[4][5] Subsequent treaties expanded the model: the South Pacific Nuclear Free Zone Treaty (Rarotonga) in 1985 encompassed Australia, New Zealand, and island nations; the Southeast Asia Nuclear-Weapon-Free Zone Treaty (Bangkok) in 1995 included ASEAN states; the African Nuclear-Weapon-Free Zone Treaty (Pelindaba) in 1996 covered the continent; and the Central Asian Nuclear-Weapon-Free Zone Treaty (Semipalatinsk) in 2006 addressed post-Soviet territories.[3][6] Together, these five treaties, alongside unilateral declarations like Mongolia's 1992 nuclear-weapon-free status and the Antarctic Treaty System's 1959 ban on nuclear activities, denuclearize vast swaths of the Southern Hemisphere and parts of the Northern, encompassing over 100 states and promoting norms against proliferation despite persistent challenges from non-signatory nuclear powers' incomplete adherence to protocols.[3][7] While empirically effective in preventing indigenous nuclear programs within their bounds—evidenced by zero verified violations—the zones' deterrent value remains contested, as external nuclear threats persist unabated, underscoring causal limits where geographic isolation aids compliance but global asymmetries undermine comprehensive security.[8] Efforts to establish additional zones, such as in the Arctic or Middle East, have stalled amid geopolitical disputes, highlighting tensions between regional initiatives and great-power rivalries.[8]