{
  "question_id": "W139",
  "slug": "nuclear-weapon-used-in-war",
  "title": "A nuclear weapon is detonated in an attack",
  "type": "binary",
  "resolution": {
    "levels": [],
    "values": [],
    "annotations": []
  },
  "forecasts": [
    {
      "question_id": "W139",
      "forecast_date": "2026-09-20",
      "evidence_cutoff": "2026-09-20",
      "method": "wide-v2",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": null,
      "summary": null,
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-09-30",
          "p_yes": 0.00045
        },
        {
          "period_end": "2026-12-31",
          "p_yes": 0.004448
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.007933
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.011405
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.014865
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.018313
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.021258
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.024194
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.027122
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.03004
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.032756
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.035464
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.038165
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.040858
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.043928
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.046987
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.050037
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.053076
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.056391
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.059693
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.062984
        }
      ],
      "passes": []
    },
    {
      "question_id": "W139",
      "forecast_date": "2026-09-27",
      "evidence_cutoff": "2026-09-27",
      "method": "wide-v2",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": null,
      "summary": null,
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-09-30",
          "p_yes": 0.00015
        },
        {
          "period_end": "2026-12-31",
          "p_yes": 0.004649
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.008133
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.011605
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.015064
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.018511
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.021456
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.024391
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.027318
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.030236
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.033146
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.036046
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.038938
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.041821
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.044696
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.047562
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.050419
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.053268
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.056108
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.05894
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.061763
        }
      ],
      "passes": []
    },
    {
      "question_id": "W139",
      "forecast_date": "2026-10-03",
      "evidence_cutoff": "2026-10-03",
      "method": "wide-v2.1",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": "Nuclear tests by a belligerent (e.g., a Russian Novaya Zemlya or Iranian underground test) are treated as excluded tests unless a qualifying source characterizes them as a wartime demonstration to compel; no qualifying event occurred between 2026-09-16 and 2026-10-03.",
      "summary": null,
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-12-31",
          "p_yes": 0.0029
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.0055
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.0081
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.0107
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.0133
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.0156
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.0179
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.0202
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.0225
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.0247
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.027
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.0293
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.0315
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.0338
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.036
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.0383
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.0405
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.0428
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.045
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.0472
        },
        {
          "period_end": "2031-12-31",
          "p_yes": 0.0494
        }
      ],
      "passes": []
    },
    {
      "question_id": "W139",
      "forecast_date": "2026-10-10",
      "evidence_cutoff": "2026-10-10",
      "method": "wide-v2.1",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": null,
      "summary": "No nuclear weapon has been used in war since 1945, and leaders have stepped back even in severe crises. So I put the yearly chance a little under one percent, despite a dangerous mix of conflicts: Russia's war and its threats against the Western alliance, and the American and Israeli war with Iran. That adds up to about 4 percent by the end of 2031. Open war between Russia and the Western alliance would raise it most.",
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-12-31",
          "p_yes": 0.0024
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.0045
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.0065
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.0087
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.0108
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.0127
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.0146
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.0166
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.0185
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.0204
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.0223
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.0242
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.0262
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.0281
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.03
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.0319
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.0338
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.0356
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.0375
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.0394
        },
        {
          "period_end": "2031-12-31",
          "p_yes": 0.0413
        }
      ],
      "passes": []
    },
    {
      "question_id": "W139",
      "forecast_date": "2026-10-17",
      "evidence_cutoff": "2026-10-17",
      "method": "wide-v2.1",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": null,
      "summary": "No nuclear weapon has been used in war for 81 years, including through several wars and crises involving nuclear-armed states. Today the risk is higher than usual: the US–Israel war with Iran, Russia's explicit nuclear warnings to NATO, and India–Pakistan hostility. I put the chance of a confirmed wartime nuclear detonation by the end of 2031 at about 5%. What would most raise this forecast is a direct war between Russia and NATO.",
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-12-31",
          "p_yes": 0.0027
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.0056
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.0085
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.0114
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.0143
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.0169
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.0194
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.0219
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.0244
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.0268
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.0291
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.0315
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.0339
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.0362
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.0386
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.0409
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.0432
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.0456
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.0479
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.0502
        },
        {
          "period_end": "2031-12-31",
          "p_yes": 0.0525
        }
      ],
      "passes": []
    }
  ],
  "declined": []
}