The United States and Iran reach a final written nuclear deal by December 31, 2026.
Following an interim diplomatic agreement in June 2026, negotiators set talks to draft a final framework covering Iran's nuclear program.
Across 6 frontier models answering independently, the panel thinks this is unlikely: the median is 25%.
They broadly agree, 17 points between Qwen at 31% and DeepSeek at 14%.
Money disagrees. The market sits at 14%, so the models are 11 points more confident than people with cash on the outcome.
Nothing is settled until 1 Jan 2027, when the outcome is checked against sources and every number above gets a permanent score.
- AI edge
- +11 pts
- Moved this week
- +2 pts
- Volume
- $3.3M
The models are slightly more confident than traders risking real money: 25% against 14%.
What each one said
-
QwenAlibaba
Three months left from a June interim deal; final nuclear agreements historically take years, not months.
- The JCPOA took 20 months from the 2013 interim deal to the 2015 final agreement; compressing that into ~6 months is unprecedented.
- The 60-day extendable clause signals negotiators themselves expected delays; extension mechanics suggest a final deal by year-end is aspirational.
- A shift to 'Yes' would require visible high-level political commitment (e.g., a summit or joint statement) by mid-November signaling a signed text is imminent.
31% -
GrokxAI
Whether remaining gaps on enrichment, sanctions, and verification close in the ~90 days left.
- US and Iranian teams must produce a mutually signed instrument by 31 Dec; Congress or Iranian hardliners can still veto even if diplomats agree.
- Post-interim nuclear talks (JPOA to JCPOA) historically needed 18 months; this 6-month window already half-spent sits far below that base rate.
- A late US political concession or IAEA clearance of undeclared sites would most raise the odds.
28% -
GPTOpenAI
It turns on whether the June accord’s extended window can bridge sanctions relief and verification before year-end.
- Washington and Tehran must both authorize text by Dec. 31; the initial 60-day period has likely already required extension.
- Past Iran nuclear talks took months to years, and a durable written bargain faces larger political hurdles than an interim accord.
- I would raise this sharply if negotiators publish agreed centrifuge, IAEA-access, and sanctions-relief terms by November.
27% -
GeminiGoogle
Bridging verification and sanctions relief gaps in under three months amidst domestic hardline opposition in both capitals is unlikely.
- Final JCPOA-level text required 20 months after the 2013 JPOA; three months is extraordinarily compressed for technical drafting.
- US congressional review hurdles under INARA and Iranian Supreme Leader approval requirements create severe ratification friction.
- A formal IAEA-backed framework announcement outlining specific breakout time concessions before mid-November would sharply hike odds.
23% -
ClaudeAnthropic
Whether Iran and the US can convert a fragile interim framework into a signed final deal amid deep mutual distrust by year-end.
- US-Iran nuclear diplomacy historically drags for years (JCPOA took ~2 years of formal talks after framework), leaving ~3 months tight.
- Domestic hardliners in both Tehran and Washington, plus Israel's opposition, create strong incentives to stall or scuttle a final signed text.
- A concrete positive signal would be a announced signing ceremony or IAEA-verified milestone before December, which hasn't yet been reported.
18% -
DeepSeekDeepSeek
A signed US-Iran final nuclear text in 15 months requires both capitals to absorb maximalist demands they have never met before.
- The June 14 interim pact's 60-day window lapsed in mid-August with only talks extended, not a draft; no text has been initialed as of late September.
- Any final deal needs IAEA access terms, enrichment caps, and sanctions relief sequenced through Congress and Iran's Supreme Council, each of which has killed prior…
- Base rate for comprehensive US-Iran nuclear agreements since 2013 is zero signed finals; the 2015 JCPOA took 20 months from interim to final, and this round started…
14%
6 of 6 models answered · 17 points between the highest and lowest. None was shown the market price.
Resolution criteria
On June 14, 2026, the United States and Iran announced a written diplomatic agreement, including a 60-day extendable period in which both countries committed to negotiate toward a “final deal” regarding Iran’s nuclear program and other topics. This market resolves to “Yes” if a qualifying written diplomatic instrument between the United States and Iran has been mutually signed or adopted by the specified date, 11:59 PM ET. Otherwise, this market resolves to “No.” Unless the written instrument is formally adopted without signature as described below, the instrument must be signed by both the United States and Iran. Both parties must either sign the same document or sign individual documents that substantively and directly indicate acceptance of the same underlying instrument, regardless of minor formatting, wording, or translation differences between the signed versions. Both physical signatures and officially-issued electronic signatures will qualify as signatures. If the written instrument is recognized by the United States and Iran as not requiring signature for execution, formal adoption of the instrument by both countries without signature will qualify. Formal adoption may b
Question sourced from Polymarket on 29 Sept 2026. Forecast by google/gemini-3.8-flash, anthropic/claude-sonnet-5, openai/gpt-5.6-terra, x-ai/grok-4.6, deepseek/deepseek-v4.1-flash, qwen/qwen3.8-max-0902 via OpenRouter.