On Day 52, Cease-fire Day 13, the quantitative freeze that began April 7 means no new official intercept data has entered either estimate. What has changed is the analytical reference frame: an ISW assessment (sourced in this tracker's daily log) now sits alongside the Gulf-official-anchored methodology this tracker uses. They do not agree.
| Category | ISW assessment | This tracker (best est.) | Gap | Notes |
|---|---|---|---|---|
| MRBMs fired | ~1,500 | 820–1,000 | +500–680 | ISW: retains ~1,000 of 2,500 pre-war |
| MRBMs remaining | ~1,000 | 500–1,880 | — | ISW gives point estimate; tracker gives range |
| Drones fired | ~19,000–28,000* | 8,500–9,500 | +10,000–18,000 | ISW: "well under 50% remain"; estimate derived |
| Drones remaining | <50% of pre-war | ~25,500–46,500 | — | Wide divergence; scope difference most likely |
| Total BMs fired | ~3,500–4,500* | 2,950–3,500 | +500–1,000 | SRBM totals not separately addressed by ISW |
*ISW drone and total BM figures derived from reported percentages applied to pre-war baseline ranges. The ISW assessment does not give an explicit total-fired number for all categories.
A 500–680 missile gap in MRBM accounting is not a rounding error. Five hypotheses explain most of it, and they are not mutually exclusive.
1. Pre-war baseline difference. This tracker uses a 2,000–3,000 MRBM range from open-source estimates (Atlantic, NYT, IDF, former US officials). ISW's figure of 2,500 is the low-to-mid end of that range. At equal fired figures, a lower baseline implies higher depletion — but ISW's 1,500-fired number is also absolutely higher. The baseline alone doesn't close the gap.
2. Israel theater accounting. This tracker records 400+ BMs toward Israel (NBC estimate through Apr 4), but cannot distinguish MRBM vs. SRBM in most Israel-theater strikes. Iran's Israel-directed strikes disproportionately used MRBMs — Khorramshahr-4, Emad, Fattah-2 — because only those have the range from western Iran. ISW, with access to US/Israeli intelligence, likely has a better MRBM/SRBM split for the Israel theater. If 200–300 of those 400+ Israel BMs were MRBMs (plausible), the tracker's MRBM count rises to 1,020–1,300, narrowing the ISW gap to 200–480.
3. Non-Gulf theaters. Iranian proxy networks — Iraqi Shia militia, Hezbollah — received IRGC-produced systems early in the war and used them against targets in Iraq, Syria, and the Red Sea corridor. This tracker does not count proxy-attributed strikes; ISW may. Even a handful of MRBM-equivalent strikes through proxies would add to ISW's tally without appearing in Gulf official data.
4. Underreporting adjustment differences. This tracker applies an explicit underreporting multiplier to Gulf official floor data, but that multiplier is calibrated conservatively. ISW may apply a more aggressive upward adjustment, particularly for early-war strikes (Days 1–7) where reporting was least systematic.
5. Classification differences. The boundary between long-range SRBM and short-range MRBM is fuzzy in practice. The Fateh-110 family extends into the 300km+ range; some variants may be counted as MRBMs by ISW but tracked as SRBMs here. A re-classification of 100–200 weapons at the margin would substantially close the gap.
The MRBM discrepancy is explainable. The drone divergence is not — and it matters more for assessing the resumed-conflict threat.
ISW says "well under 50% of drones remain." Applied to the pre-war range:
The gap — 12,000 to 24,000 drones — cannot be explained by baseline differences or classification ambiguities alone. Three explanations carry analytical weight:
Proxy attribution is the dominant factor. Iran's drone campaign was never solely direct-launch from IRGC units on Iranian soil. Houthi forces in Yemen, Iraqi Shia militia, and Hezbollah all launched Iranian-supplied or Iranian-design systems throughout the conflict. This tracker captures Gulf theater direct-Iran strikes via official MoD reporting. ISW's "Iranian drone" count almost certainly includes proxy-attributed strikes across a wider geographic scope — Red Sea corridor, Iraq, Lebanon, and potentially strikes ISW attributes to Iranian command direction even when physically launched by proxies.
Saudi and Iraqi theater underreporting. Saudi Arabia's reported drone figure in this tracker (680) is flagged as "Medium-Low" quality — methodologically noisy. Saudi official reporting was sparse and inconsistent. If actual drone intercepts in Saudi Arabia and adjacent Iraqi airspace were 2–4x the reported figure (consistent with patterns seen in Bahrain's 51% revision), the Gulf official floor rises by 1,400–2,720 without touching ISW's scope assumption.
Production during the war. Iran sustained some drone production through the early weeks of the conflict using Chinese chemical inputs and distributed manufacturing. ISW may be counting from a pre-war baseline while noting that some of the "fired" drones were produced after Feb 28. This tracker's pre-war figure is genuinely pre-war; ISW may effectively be measuring total-produced-and-fired rather than fired-from-stockpile.
This is where the divergence stops being a methodology puzzle and becomes operationally significant. The two estimates point to very different threats if Islamabad Round 2 fails.
| Scenario | MRBM threat if conflict resumes | Drone threat if conflict resumes | Strategic implication |
|---|---|---|---|
| This tracker is right | 820–1,000 MRBMs fired; 500–1,880 remaining; ~8–12 BMs/day at reduced launcher capacity | 80%+ of pre-war stock intact; 25,500–46,500 available; persistent pressure sustainable for years | Drone war of attrition against Gulf energy infra; BM harassment secondary. Coalition interceptor gap is the acute problem. |
| ISW is right | ~1,500 MRBMs fired; ~1,000 remaining; sharper MRBM depletion than tracked here | <50% of pre-war intact; substantial drone depletion across all theaters including proxies; less sustainable pressure | Both BM and drone threats more degraded than tracker shows. Iran's strategic position weaker; coalition leverage at Islamabad stronger. |
| Launchers (both agree) | ~102 remaining (68–135 range); ~50 days to zero at pre-ceasefire rate. This constraint is consistent across both estimates. | Regardless of MRBM stockpile, launcher scarcity caps BM output. Drones don't need TELs — drone threat depends on production/supply, not hardware count. | |
The critical asymmetry: Iran's launcher count is the one estimate both approaches effectively agree on. The hardware was physically destroyed — ISW and coalition defense sources align on ~300–340 launchers destroyed or combat-ineffective. That ceiling (~8–18 BMs/day if resumed) holds under either stockpile accounting.
Where ISW's higher drone depletion figure, if correct, significantly changes the picture: it undermines the "drone long war" thesis. If Iran has consumed 60% or more of its drone stock rather than 17–27%, the sustained pressure campaign against Gulf energy infrastructure becomes finite rather than open-ended. Iran's incentive to extend the cease-fire would be stronger under ISW's numbers — not just for diplomatic reasons, but because its most durable offensive asset is more depleted than the tracker's current estimate shows.
Two things are worth distinguishing: what the tracker's methodology is designed to measure, and what ISW's methodology is likely measuring.
This tracker uses UAE MoD and Bahrain Defence Force official cumulatives as its highest-confidence anchor. Those are direct-Iran strikes against Gulf theater targets. The tracker then applies upward adjustments for underreporting and other theaters, but retains the Gulf-official data as the floor. That produces a conservative, well-sourced lower bound with explicit uncertainty ranges.
ISW's methodology is broader: it integrates US intelligence community assessments, Israeli military reporting, and multi-theater attribution. It likely captures the full scope of IRGC-directed strikes — including those conducted through proxies, in non-Gulf theaters, and with production-during-war drones. That produces a higher figure that is probably more accurate for total-system expenditure but harder to audit from open sources.
The two approaches are complements, not competitors. The practical synthesis:
The divergence between these two estimates will either narrow or widen in the next 72 hours depending on what happens at Islamabad. If talks produce a 45-day extension, figures remain frozen. If talks collapse and fire resumes, the tracker's confirmed-floor methodology will pick up new official intercept data from UAE and Bahrain within 12–24 hours of any renewed strikes — and those data points will begin to discriminate between the two estimates.