Scan: Will the U.S. invade Iran before 2027?

date	predicted	market price	confidence
2026-08-25	14%	16%	70%
2026-08-18	17%	18%	62%
2026-07-30	21%	24%	38%

1. Planner Fable 5.1 · Fermi decomposition + tool plan

Tools chosen: polymarket_direct polymarket_related kalshi_related claude_news article_search gdelt_news wikipedia code_execution

Sub-questions (Fermi decomposition)

What is the current state of US-Iran relations and nuclear negotiations, and has the Trump administration signaled any intent for ground operations or territorial seizure in Iran (e.g., Kharg Island, Strait of Hormuz islands)?
What is the current US military force posture in the Middle East (carrier groups, troop deployments, Marine expeditionary units) and does it indicate preparation for a ground offensive versus standoff strikes?
How often historically have US-Iran crises (1979, 1988, 2019-2020, June 2025) escalated to US forces attempting to seize Iranian territory, and what is the base rate for such invasions?
Are there active Iran-Israel or Iran-Gulf conflict escalations that could draw the US into a land campaign before 2027?
What do related Polymarket and Kalshi markets price for US strikes on Iran, Iran regime change, or US-Iran conflict in 2026, and how do they compare to this invasion market?
Has any credible source reported US planning for seizing Iranian territory (e.g., islands in the Persian Gulf) as a coercive lever, and what is the political/congressional appetite for such an operation?

Planner reasoning

This is a Polymarket geopolitical question about a US ground invasion of Iran (establishing control over territory, not just airstrikes) by end of 2026. The market price is the primary anchor; key drivers are current US-Iran tensions, nuclear negotiations, Israeli actions, US force posture in the region, and stated administration intent. Airstrikes like June 2025 would not count, so distinguishing strikes from territorial offensives is critical.

2. Research Parallel tool calls

tool	status	time	items	summary
polymarket_direct	OK	0.2s	1	## This Market's Polymarket Data Will the U.S. invade Iran before 2027? - Current price (probability): 16.50% - 7-day price change: +1.00% - 30-day price change: -1.00% - Total volume: $66,566,890 (USD notional) - Price range: 11.50% - 31.50% - Data points: 91 days
polymarket_related	OK	1.7s	15	Polymarket search over 5 keyword(s), kept 15 matches. keyword 'Iran': 5 markets \| keyword 'US Iran': 5 markets \| keyword 'Iran strike': 0 markets \| keyword 'Iran regime': 5 markets \| keyword 'Khamenei': 0 markets
kalshi_related	OK	3.0s	2	2 related markets / summaries. keyword 'Iran': no matches \| keyword 'US strike Iran': ok \| keyword 'Iran war': ok
claude_news	OK	22.0s	13	## Key Findings - Major war already underway since Feb 2026: The 2026 Iran war is a conflict centered on Iran that was initiated by the United States and Israel on February 28, 2026, embroiling the entire Middle East region. When Tehran would not accede to U.S. demands to end all nuclear enr
article_search	OK	1.3s	28	Fetched 28 unique articles across 4 queries (lookback=45d). 'US Iran military strike ground invasion': 10 articles \| 'Trump Iran nuclear negotiations': 10 articles \| 'US troops Middle East Iran Kharg Island': 10 articles \| 'Israel Iran war escalation': 10 articles
gdelt_news	OK	103.8s	20	GDELT: 20 articles across 3 queries (lookback=30d). 'United States invade Iran': 10 hits \| 'US military Iran ground forces': 10 hits \| 'Iran Strait of Hormuz US Navy': error GDELT rate-limited after retries (429)
wikipedia	OK	0.4s	4	Fetched 4 Wikipedia entries (0 missing pages).
code_execution	OK	20.7s	0	## Base Rate Analysis: U.S. Invasion of Iran Before 2027 Historical base rate (46 years, 0 ground invasions since 1979): - Laplace/add-1 estimate (Beta(1,1) prior): 2.08% annual probability - Jeffreys prior (Beta(0.5,0.5)), more conservative for rare events: 1.06% annual - Weakly-inform

3. Evidence Brief Sonnet 5 · 7195 chars

# Current state A US/Israel-Iran war began Feb 28, 2026 (airstrikes, assassination of Khamenei), was paused by a June 14, 2026 ceasefire/MOU, but sporadic strikes (tankers, missiles, naval clashes) have continued through Sept 2026. Despite substantial ground-capable force buildup (82nd Airborne, Marines, MEUs) and Pentagon planning for limited raids (e.g., Kharg Island), the US has explicitly stopped short of a full ground invasion or territorial seizure — Hegseth denies "boots on the ground," and Trump is signaling a desire to end the war via negotiated deal rather than escalate. # Timeline of key events - 2025-06-13/24: Twelve-Day War — Israel strikes Iran; US bombs three nuclear sites (Operation Midnight Hammer, June 22) but takes no other offensive action; ceasefire June 24. (confirmed, Wikipedia) - 2025-11-04: Market's baseline date for "de facto controlled" territory (structural, per rules). - 2026-02-28: US and Israel launch joint attack on Iran, kill Supreme Leader Khamenei, start "2026 Iran war." (confirmed, Wikipedia/Britannica) - 2026-03-25/30: US surges ground-capable forces (82nd Airborne paratroopers, Marines) to region; Pentagon drafts plans for special-forces raids/seizure of Kharg Island and coastal sites, explicitly stopping short of full invasion. (reported, Al Jazeera/Military.com/Soufan Center/Malay Mail) - 2026-06-14: US-Iran ceasefire/MOU announced, Pakistan/Qatar-mediated, 60-day extension framework for settlement. (confirmed, Wikipedia) - 2026-07-24: Foreign Policy analysis: US has forces to seize islands like Kharg but experts skeptical of large-scale ground campaign; force posture consistent with raids, not sustained invasion. (reported) - 2026-08-25 to 09-14: Ceasefire fragile — mine-clearing claims, tanker strikes/sinkings, missile exchange with Jordan, downed US aircraft, IRGC counter-cell strikes; Trump states war "will end immediately after our election" and Iran "wants to make a deal." (confirmed multiple outlets: CNN, WaPo, CBS, RFE/RL) # Event Will the U.S. commence a military offensive intended to establish control over any portion of Iranian territory before Jan 1, 2027? # Outcomes to forecast Yes / No # Kalshi market anchor No direct Kalshi price returned (kalshi_direct not present in tool output; kalshi_related found no matching Iran invasion market). **Primary anchor is Polymarket**, same event: YES ~16.5%, +1% (7d), -1% (30d), range 11.5%–31.5% over 91 days, volume $66.6M — high liquidity, price has come well off its 31.5% peak (likely during Feb-Mar 2026 war outbreak) and stabilized in mid-teens. # Resolution source Not run — no resolution_source tool output provided. # Sub-question answers 1. **US-Iran relations/negotiations**: Active war since Feb 2026, ceasefire/MOU since June 14, 2026, fragile with recurring strikes through Sept 2026; no reported intent for ground occupation — Hegseth denies boots on ground, Trump seeks a deal. [Wikipedia, military.com, RFE/RL] 2. **Force posture**: 2,000–3,000 82nd Airborne paratroopers plus Marines/MEUs deployed, with Pentagon weighing up to 10,000 more troops; experts describe posture as "rapid-response, modular... designed for raids, seizures of key terrain, and short-duration missions," not sustained ground campaign. [Foreign Policy, Soufan Center, Al Jazeera] 3. **Base rate**: Zero US ground invasions of Iran in 46 years (1979–2025); statistical model estimates ~7–9% probability of full invasion by end-2026 after applying a 3x–5x "heightened tension" multiplier to base rate. [code_execution] 4. **Active escalation risk**: Yes — Aug–Sept 2026 saw tanker strikes/sinkings, missile barrages at Jordan, a downed US aircraft, and IRGC operations against US/Israel-linked cells, but confined to airstrikes/naval actions, not ground incursion. [CNN, WaPo, CBS] 5. **Related markets**: This Polymarket event itself at 16.5%; "Iranian regime fall before 2027" at 6.5%; Israel-Iran ceasefire continuation markets range 66–93% depending on date; US-Iran diplomatic meeting by Dec 2026 at 37.5% — suggesting markets see de-escalation/diplomacy as more likely than invasion. 6. **Territorial seizure planning**: Credible reporting (Foreign Policy, Malay Mail) confirms Pentagon planning for raids on Kharg Island/coastal sites as coercive leverage, but explicitly "stops short of full-scale invasion." Congressional appetite appears constrained — reports of "Trump draft" backlash concerns and prior partisan splits over war constitutionality. [alternet.org, Wikipedia] # Key facts (high-confidence, factual) 1. [Wikipedia] Full-scale US/Israel war on Iran began Feb 28, 2026; Khamenei killed. 2. [Wikipedia] Ceasefire/MOU reached June 14, 2026, mediated by Pakistan/Qatar. 3. [Foreign Policy/Soufan Center] Force posture built for raids/seizures, not sustained occupation. 4. [Military.com] Hegseth: "We've taken control of Iran's airspace and waterways without boots on the ground." 5. [CNN/WaPo] Strikes/counterstrikes continued into Sept 2026 despite ceasefire. 6. [code_execution] Zero precedent for full US ground invasion of Iran historically. # Cross-market signals - Polymarket (this event): 16.5% YES, stable/slightly declining from Feb-Mar 2026 peak. - Polymarket related: Iran regime fall <2027 ~6.5%; ceasefire-continuation markets 66–93% (bullish on non-escalation); nuclear deal by Sept 2026 ~0.6% (near-zero deal odds, but doesn't imply invasion). - Kalshi: no direct comparable market found. - No sportsbook data available. # Analyst opinions and speculation - Experts (Foreign Policy, Al Jazeera) skeptical of large-scale ground operation despite capability; view current buildup as raid-oriented. - Trump rhetoric (Aug–Sept 2026) leans toward deal-seeking/war-ending, not escalation, though prior "two weeks" deal claims proved unreliable — treat as rumored/unreliable framing, not fact. - Domestic political risk (draft backlash commentary) suggests limited appetite for full invasion. # Directional lean per outcome - **Yes**: Active war state, force buildup capable of seizing islands (Kharg), history of the conflict already crossing thresholds unprecedented since 1979 (Khamenei killed, sustained conflict) — real tail risk given active hostilities. - **No**: Explicit reporting that plans "stop short of full invasion"; Hegseth/Trump statements against ground occupation; strong historical base rate (0 invasions in 46 yrs); markets pricing modest probability (~16.5%); Trump signaling war-ending rhetoric. # Gaps / unknowns - No live Kalshi YES price captured in this research pull. - No resolution_source page fetched. - Ambiguity on how "control over any portion of Iran" would be adjudicated given already-conducted raids/strikes on Iranian soil/islands (Kharg bombed but not occupied) — precise resolution criteria interpretation uncertain. - Trajectory of ceasefire durability post-Sept 2026 unclear; outcome highly sensitive to further escalation events not yet reported. # Calibration anchors - Polymarket YES price (anchor): 16.5%, range 11.5–31.5% over past 91 days. - Historical base rate: 0 full ground invasions of Iran in 46 years; model-adjusted estimate ~7–9% for 13-month window under heightened tension.

4. Forecasters 5 draws · Fable 5.1 + GPT-5.6 Sol

claude-fable-5-1

50% conf

Yes	14%
No	86%

The Polymarket anchor for this exact event sits at ~16.5% YES and has drifted down from a 31.5% peak during the Feb–Mar 2026 war outbreak, reflecting a ceasefire/MOU since June 14 and Trump's deal-seeking rhetoric ('war will end immediately after our election'). Force posture (82nd Airborne, MEUs) is real and Pentagon planning for Kharg Island/coastal seizures would plausibly resolve YES, so tail risk is materially above the historical ~7–9% model estimate — but reporting consistently says plans 'stop short of full invasion' and Hegseth explicitly touts 'no boots on the ground.' Ceasefire-continuation markets at 66–93% and regime-fall at 6.5% signal markets expect de-escalation over the remaining ~3.5 months. I shade slightly below the anchor given the short window and stated political intent to end rather than expand the war, while keeping meaningful probability for a coercive island seizure if the fragile ceasefire collapses.

claude-fable-5-1

52% conf

Yes	15%
No	85%

No Kalshi price was available, so the anchor is the highly liquid Polymarket market on the same question at ~16.5% YES, well off its 31.5% peak during the Feb–Mar 2026 war outbreak. The situation carries real tail risk: an active war state with a fragile June 14 ceasefire, continued strikes through Sept 2026, and a ground-capable force posture with Pentagon planning for Kharg Island/coastal seizures that would plausibly satisfy the low 'any portion of Iranian territory' threshold. Against this, credible reporting says plans explicitly 'stop short of full invasion,' Hegseth denies boots on the ground, Trump is signaling a negotiated end to the war, related markets price ceasefire continuation at 66–93% and regime fall at only 6.5%, and the historical base rate of US ground seizures of Iranian territory is zero. With roughly 3.5 months remaining, I land slightly below the market at 15% YES, reflecting deal-seeking rhetoric while respecting the elevated risk of a limited coercive seizure if the ceasefire collapses.

claude-fable-5-1

52% conf

Yes	14%
No	86%

The primary anchor is Polymarket at ~16.5% YES ($66.6M volume, stable in the mid-teens after a 31.5% peak during the Feb–Mar 2026 war outbreak). The evidence points toward No: despite a large ground-capable buildup (82nd Airborne, MEUs) and credible Pentagon planning for Kharg Island/coastal raids, reporting explicitly says plans 'stop short of full invasion,' Hegseth denies boots on the ground, and Trump's Aug–Sept rhetoric is deal-seeking with the war to 'end after our election.' The buildup has existed since March without any territorial seizure, the ceasefire/MOU has held in fragile form for three months, and only ~3.5 months remain in the window; related markets (regime fall 6.5%, ceasefire continuation 66–93%) also lean toward non-escalation. The real tail is a ceasefire collapse leading to a coercive Kharg Island seizure, which would plausibly count under 'control over any portion' — this keeps YES meaningfully above the ~7–9% base-rate model, so I shade slightly below the market at 14%.

gpt-5.6-sol

68% conf

Yes	15%
No	85%

The 16.5% Polymarket YES price is the best available anchor, as no direct Kalshi price was returned. Negotiations, Trump’s war-ending rhetoric, and Hegseth’s denial of boots on the ground point toward No, while the historical base rate and related markets also favor non-invasion. The deployed airborne and Marine forces are configured for limited raids or key-terrain seizures rather than sustained occupation, though planning around Kharg Island and continuing clashes create a meaningful Yes tail. I move slightly below the market anchor because the ceasefire and explicit policy signals outweigh that escalation risk, while retaining 15% because even a limited territorial seizure may satisfy the event’s broad wording.

gpt-5.6-sol

58% conf

Yes	18%
No	82%

The 16.5% Polymarket YES price is the best available consensus anchor because no direct Kalshi price was returned. The ceasefire, deal-seeking rhetoric, historical absence of a U.S. ground invasion, and expert assessments that deployed forces are insufficient for a sustained campaign point toward No. However, continuing clashes and credible planning for short-duration seizures of Kharg Island or coastal terrain create a meaningful Yes tail, especially because the event requires control of only some Iranian territory rather than a full-scale invasion. I therefore place YES slightly above the market anchor while retaining No as the clear favorite.

6. Final plain mean of 5 draws

15% (56% confidence)

Yes: 15% No: 85%

Mean of 5 draws (0.14, 0.15, 0.14, 0.15, 0.18). The Polymarket anchor for this exact event sits at ~16.5% YES and has drifted down from a 31.5% peak during the Feb–Mar 2026 war outbreak, reflecting a ceasefire/MOU since June 14 and Trump's deal-seeking rhetoric ('war will end immediately after our election'). Force posture (82nd Airborne, MEUs) is real and Pentagon planning for Kharg Island/coastal seizures would plausibly resolve YES, so tail risk is materially above the historical ~7–9% model estimate — but reporting consistently says plans 'stop short of full invasion' and Hegseth explicitly touts 'no boots on the ground.' Ceasefire-continuation markets at 66–93% and regime-fall at 6.5% signal markets expect de-escalation over the remaining ~3.5 months. I shade slightly below the anchor given the short window and stated political intent to end rather than expand the war, while keeping meaningful probability for a coercive island seizure if the fragile ceasefire collapses.

Pipeline Timing

Total pipeline time: 187.9s

Per-tool research timings shown in the Research section above.