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Iran Conflict 2026
21MAY

Iran's salvos shrink from hundreds to 40

3 min read
09:55UTC

Wave 17 of Operation True Promise 4 carried more than 40 missiles. The opening barrages ran to hundreds. Three explanations compete, and the answer determines how this war ends.

ConflictDeveloping
Key takeaway

Wave 17 at 40 missiles signals Iran has either consumed its mass-salvo inventory or is transitioning to precision targeting of high-value strategic assets — and the two possibilities imply opposite threat trajectories.

The IRGC launched waves 16 and 17 of Operation True Promise 4 on Wednesday. Wave 17 comprised "more than 40 missiles" — down from early-conflict salvos that overwhelmed Gulf air defences with hundreds of projectiles per wave. The IRGC has maintained its numbered wave system throughout the conflict, averaging roughly two named waves per day, which indicates organisational continuity even as volume has collapsed.

Three explanations are consistent with the data. attrition: US and Israeli forces have struck more than 2,000 targets since operations began, and B-2 bombers have specifically targeted hardened underground missile facilities . Physical destruction of launchers and stockpiles would produce exactly this curve. Conservation: Iran's foreign minister acknowledged earlier this week that military units are operating outside central government direction , but the persistence of the numbered wave structure suggests the IRGC's own command chain — distinct from the civilian government — retains coordination. A force aware of its finite inventory may be rationing for maximum political leverage rather than firing to exhaustion. Degraded confidence: if Gulf state and Coalition interception rates are high enough — the UAE alone intercepted 165 ballistic missiles in the opening days — large salvos become expensive theatre rather than effective military action, and smaller, more targeted strikes may reflect adaptation rather than weakness.

The distinction carries operational weight. Iran entered this conflict with its conventional missile force as the primary deterrent against regime-threatening attack — the "conventional shield" Defence Secretary Hegseth referenced at his first Pentagon briefing . If that shield is being physically dismantled, Iran's remaining options narrow to asymmetric warfare through proxies and allied militias, acceptance of terms, or escalation into domains it has so far avoided. The declining salvo rate is a fact. What it means is the central analytical question of the war's next phase.

Deep Analysis

In plain English

Iran has been firing missiles in organised waves — think of them as successive rounds of an attack. Early waves were enormous: hundreds of missiles at a time, designed to overwhelm Israeli and US missile defences by sheer volume. By wave 17, that number has dropped to around 40. This could mean Iran is simply running low on missiles. Or it could mean Iran has switched strategies — saving its most capable remaining weapons for one carefully chosen, high-value target. A declining number is not the same as a declining threat, and these two possibilities require completely different responses.

Deep Analysis
Synthesis

The 'Operation True Promise' naming sequence — this being TP4 — signals Iran framed this conflict as the continuation of a campaign that began in April 2024, not a new war. This framing has a significant implication for ceasefire terms: Iran is not resolving a discrete crisis but concluding a multi-year campaign with defined political objectives (deterrence restoration after the Soleimani killing, Hamas war, and Nasrallah assassination). The bar for a negotiated exit is therefore higher than a simple ceasefire — Iran needs something it can frame as achieving the campaign's original purpose.

Root Causes

Iran's pre-war ballistic missile stockpile was estimated by multiple Western intelligence assessments at 2,000–3,000 units. At 17 waves with early salvos of hundreds and later salvos declining to tens, conservative arithmetic places total expenditure at 1,500–2,500 missiles. Independent of any infrastructure attrition, simple stockpile depletion creates genuine launch-rate pressure. This structural constraint is invisible in the body's analysis and is consistent with all three of the explanations the body presents.

Escalation

The transition to smaller salvos creates a qualitatively different risk profile. High-volume attacks are somewhat predictable in targeting logic — they aim at broad area denial and interception exhaustion. A single precise strike on a critical node — a desalination plant, a financial data centre, or a nuclear-adjacent facility — could be more consequential than 200 intercepted ballistic missiles. Declining salvo volume should not be read as declining threat severity.

What could happen next?
  • Risk

    Transition to low-volume precision salvos increases the probability of a single high-consequence strike on critical infrastructure that mass interception rates cannot prevent.

    Immediate · Assessed
  • Meaning

    Wave 17's composition suggests Iran has moved past its mass-saturation phase; the remaining inventory is likely weighted toward higher-capability, harder-to-intercept systems.

    Immediate · Suggested
  • Consequence

    If remaining Iranian salvos include advanced hypersonic or cruise components held back from earlier waves, the interception success rates that shaped US and Israeli public confidence may not hold.

    Short term · Suggested
  • Precedent

    This is the first large-scale operational test of echelonment-style saturation doctrine against a US-integrated multi-layer missile defence architecture, generating lessons for all future adversaries and for US missile defence procurement.

    Long term · Assessed
First Reported In

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GlobalSecurity· 4 Mar 2026
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Causes and effects
This Event
Iran's salvos shrink from hundreds to 40
The wave-by-wave data is the most granular publicly available measure of Iran's remaining conventional deterrent. The rate of decline — and its cause — determines whether Iran retains the capacity to impose costs that alter Washington's calculus, or whether the second US assault will face a functionally disarmed adversary.
Different Perspectives
Turkey (Shakarab consideration)
Turkey (Shakarab consideration)
Ankara serves as one of two Western-adjacent Iran back-channels while Turkish national Gholamreza Khani Shakarab faces imminent execution on espionage charges in Iran. President Erdogan cannot deflect the domestic political crisis that a Turkish execution would trigger, which would force suspension of the mediating role.
Germany (Bundestag gap)
Germany (Bundestag gap)
Belgium, Germany, Australia, and France committed Hormuz coalition hardware on 18 May. Germany's Bundestag authorisation for the coalition deployment remains pending, creating a constitutional gap between the commitment announced and the parliamentary mandate required to operationalise it.
IEA and oil market analysts
IEA and oil market analysts
The IEA's $106 May Brent projection met the market in one session on 20 May as Brent fell 5.16% on diplomatic optimism. Goldman Sachs and Morgan Stanley's two-layer premium framework holds: the kinetic component compressed; the structural insurance component tied to Lloyd's ROE remains unresolved.
Hengaw
Hengaw
Documented the dual Kurdish execution at Naqadeh on 21 May, the two Iraqi-national espionage executions on 20 May, and Gholamreza Khani Shakarab's imminent execution risk. The 24-hour cluster covers two executions at one facility, the first foreign-national espionage executions, and a Turkish national whose death would suspend Ankara's mediation.
Lloyd's of London
Lloyd's of London
Hull rates stand at 110-125% of vessel value on the secondary market; the Joint War Committee has conditioned cover reopening on written ROE from the coalition or PGSA. The Majlis rial bill makes any compliant ROE structurally impossible to draft while the PGSA's yuan portal remains its operational mechanism.
United Kingdom and France (Northwood coalition)
United Kingdom and France (Northwood coalition)
The 26-nation coalition paper requires Lloyd's to see written rules of engagement before Hormuz war-risk cover reopens. The Majlis rial bill adds a second governance incompatibility on top of the unpublished PGSA fee schedule; coalition ROE cannot mention rial without conceding Iranian sovereignty over the strait.