Coming September 2026
First Island Brittleness (FIB)
A quarterly 0–100 index measuring the rate at which the US-allied position across the First Island Chain is decaying versus being rebuilt. Published quarterly. Open methodology. Free to read.
Brittleness is a rate, not a state.
The claim
The standard Indo-Pacific discourse asks “can the US win?”— a capability question. FIB asks “how fast is the position decaying versus how fast is it being rebuilt?” — a rate-of-change question. The brittleness is the gap between those rates.
The three pillars
Composite weighted 35/40/25. Weights immutable for twelve months per methodology version.
Pillar 1 · 35%
Munitions Latency
Cancian CSIS 2023 consumption-weighted mean of days to replace one day of fire. The more we fire it, the more its brittleness pulls the score.
Pillar 2 · 40%
Industrial Regen Velocity
PLAN production-weighted: Beijing's investment is the revealed preference for what threatens us. Supplier-level health drawn from Iron Command's own defence-industrial database.
Pillar 3 · 25%
Allied Political Half-Life
US-forward-force-weighted across Japan, Korea, Philippines, Australia, Taiwan. Per country, 50/50 state vs trajectory across five signals.
How each release reads
Two cadences. A quarterly composite you can benchmark against over years, and a monthly political read that moves with events.
Quarterly · Layer 1
The FIB level
The headline 0–100 composite. Brittleness is structural, so the level is a benchmark you track and argue about over years, not a number that lurches each quarter. This is the figure the press cites and clients hold against their own assessment.
Quarterly · Layer 2
What moved and why
Every quarter decomposes the change into per-pillar contributions — which pillar moved the index, by how much, and the driver behind it. The story is in the decomposition, even in a quarter where the headline holds. A flat level is itself a finding.
Monthly · Layer 3
Allied Political Half-Life
The fastest-moving pillar, published monthly between quarterly reports — elections, communiqués, and coercion incidents absorbed or conceded. The early-warning line on allied resolve, ahead of the next composite.
What FIB deliberately does not do
- — Not a war probability. No P(Taiwan invasion) attached. This is about decay rate, not forecast.
- — Not platform-by-platform tactical assessment. USNI and Sub Brief already do that better than us.
- — Not US-only. The allied position is the position. That's what makes FIB different from Pentagon-internal scoring.
- — Not classified-data-dependent. All inputs are open-source per ICD 203. Anyone can re-run a published quarter.
Open methodology, locked weights
Version 1.0 locked 17 May 2026. Pillar weights immutable until 17 May 2027. Every quarterly score ships with a full per-pillar breakdown so anyone can audit it. Weights themselves are anchored to external data — Cancian CSIS for munitions consumption, PLAN production rates for industrial weighting, US forward-deployed force structure for country weighting — not analyst opinion.
Full methodology paper publishes alongside the first quarterly report in September 2026.
External readers
Three independent readers reviewing the methodology before publication. Credited by name in the methodology paper.
Mick Ryan, AM
Lowy Institute · CSIS
Christopher Sharman
CMSI, US Naval War College
Drew Thompson
RSIS Singapore · ex-DoD
Be the first to read it
Q3 2026 publishes end of September
The first FIB quarterly report drops in late September. Send us your email and you'll get it the day it publishes, plus the quarterly thereafter.
Register interest →Or work with Iron Command directly via the Fractional Geopolitical Advisor seat — every retainer client gets the FIB read built into their weekly brief.