Skip to content
Iran Conflict 2026
20APR

Interceptor Crisis Reaches Projected Depletion Window

2 min read
10:10UTC

THAAD exhaustion may have arrived silently. Arrow-3 stocks at 81% depletion. JASSM-ER reserves for a Taiwan contingency spent in Iran.

ConflictDeveloping
Key takeaway

Defence and strike stocks deplete simultaneously; production cannot catch either.

The Royal United Services Institute projected in early March that THAAD stocks would exhaust within one month; that window has now closed . The Payne Institute estimates one-third of the THAAD stockpile has been consumed. Annual production capacity: roughly 100 interceptors. No emergency resupply has been announced.

Arrow-3 stocks remain at 81% depletion or worse . Combined with the consumption of more than 1,000 JASSM-ERs drawn from Pacific Command stocks , the US is simultaneously drawing down its primary standoff strike capability and its missile defence inventory. The restock gap for JASSM-ERs runs 18 to 30 months under even surge production. The weapons designed for a Taiwan contingency are being spent in Iran.

The arithmetic runs one direction. Iran does not need to win the air war. It needs to outlast the interceptors. With Russia supplying an estimated 1,000 Geran-2 drones per day , the attritional equation favours the side that can produce munitions at industrial scale against a defence architecture that cannot replenish at any scale.

If THAAD and Arrow-3 stocks cross critical thresholds without resupply, the US and Israel face a binary choice: accept degraded air defence or reduce the operational tempo that is consuming the interceptors. Either path changes the war's trajectory.

Deep Analysis

In plain English

The missiles that defend against Iranian attacks are running out, and the factories that make them produce too slowly to catch up. At the same time, the cruise missiles being used to attack Iran were originally set aside for a possible conflict with China, leaving the Pacific less defended. Iran does not need to win; it needs to keep firing until the defences run dry.

Deep Analysis
Root Causes

The US defence-industrial base was optimised for precision and quality over volume. Annual production rates (100 THAAD interceptors, 396 JASSM-ERs at standard rate) assumed deterrence and short, decisive conflicts, not a sustained attritional war against an adversary supported by Russian industrial-scale drone production.

Escalation

Structurally escalatory. As defensive stocks deplete, the risk of successful Iranian strikes on Gulf energy infrastructure increases. This could trigger oil price spikes, Gulf military responses (under the Article 51 framework), or US escalation to compensate for degraded defence with increased offensive operations.

What could happen next?
  • Missile defence architecture protecting Israel, UAE, and US forces degrades materially by mid-to-late April

    weeks · Assessed
  • JASSM-ER depletion weakens US deterrence posture against China through at least mid-2028

    years · Assessed
  • Degraded air defence increases risk of successful strikes on Gulf energy infrastructure

    weeks · Suggested
First Reported In

Update #60 · Pakistan's Ceasefire Plan Fills the Vacuum

Defence Security Asia / RUSI· 6 Apr 2026
Read original
Different Perspectives
Global South governments (Indonesia, Brazil, South Africa)
Global South governments (Indonesia, Brazil, South Africa)
Neutrality was possible when the targets were military. 148 dead schoolgirls made it impossible — no government can explain that away to its own citizens.
Trump administration
Trump administration
Oscillating between claiming diplomatic progress and threatening escalation, while deploying additional ground forces to the Gulf.
Israeli security establishment
Israeli security establishment
Fears a rapid, vague US-Iran agreement that freezes military operations before the IDF achieves what it considers full strategic objectives. A senior military official assessed the campaign is 'halfway there' and needs several more weeks.
Iraqi government
Iraqi government
Iraq's force majeure is the position of a non-belligerent whose entire petroleum economy has been paralysed by a war between others — storage full, exports blocked, production being cut with no timeline for resumption.
Russia — Ambassador Vassily Nebenzia
Russia — Ambassador Vassily Nebenzia
Moscow calibrated its position between Gulf states and Iran: abstaining on Resolution 2817 rather than vetoing it, signalling it would not block protection for Gulf states, while refusing to endorse a text that ignores the US-Israeli campaign it regards as the conflict's proximate cause. Russia proposed its own ceasefire text — which failed 4-2-9 — allowing Moscow to claim the peacemaker role while providing Iran with satellite targeting intelligence, a duality consistent with its approach in Syria.
France — President Macron
France — President Macron
France absorbed its first combat death in a conflict it has publicly declined to join. The killing of Chief Warrant Officer Frion in Erbil forces Macron to choose between escalating involvement and accepting casualties from the margins.