North Korea acceded to the Non-Proliferation Treaty in 1985 before announcing its withdrawal in 2003.
Notes on verification
Multiple independent, credible sources (NTI, Brookings, NCNK, contemporary news) corroborate both the 1985 accession and 2003 withdrawal dates. [tier=silver indep_score=0.812 clusters=4 claim_tier=notable]
Sources
- List of states with nuclear weapons (wikipedia)
- https://www.nti.org/analysis/articles/north-korea-nuclear-disarmament/ (corroboration)
- https://www.brookings.edu/articles/north-korea-a-rogue-state-outside-the-npt-fold/ (corroboration)
- https://www.ncnk.org/resources/briefing-papers/all-briefing-papers/north-koreas-nuclear-weapons-program (corroboration)
- https://www.globalsecurity.org/wmd/library/news/dprk/2003/dprk-030110-korea-net01.htm (corroboration)