Sovereignty is structure.
We measure it.

The International Sovereignty Index quantifies external supplier concentration — inaugural release: EU-27 member states — using a Herfindahl-Hirschman framework applied to 6 strategic axes of external exposure.

This is not a risk score. It is a structural measurement — a precise rendering of how concentrated each nation’s external suppliers are, across energy, finance, defense, technology, critical inputs, and logistics.

Explore the Mapv0.1 · 2022–2024 · 27/27 countries

Cohort Mean Axis Exposure

ENERGYHHI mean

0.3652

FINANCIALHHI mean

0.1480

DEFENSEHHI mean

0.5732

TECHNOLOGYHHI mean

0.2108

CRITICAL INPUTSHHI mean

0.2515

LOGISTICSHHI mean

0.5176

0.000.50

EU-27 Structural Exposure

Composite ISI scores mapped across 27 member states. Click any country for full axis-level detail.

Interactive

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HHI Concentration< 0.150.15–0.240.25–0.49≥ 0.50No data

Structural Outliers

Countries exhibiting the most notable structural concentration patterns across the EU-27 cohort.

Highest Logistics Concentration

1.0000

Logistics axis HHI

Malta

Most concentrated logistics supplier structure in the cohort

Most Diversified

0.2357

Composite ISI

France

Lowest composite ISI — broadest structural spread

Largest Deviation from Mean

+0.1731

Δ from EU mean (0.3444)

Malta

Greatest distance from the cohort composite average

Most Uneven Profile

0.1242

Axis score variance

Malta

Highest axis-level variance — structural imbalance

Executive Summary

Countries Scored

27 / 27

Cohort scope (EU-27)

Composite Mean

0.3444

Cohort average

Composite Median

0.3403

Cohort midpoint

Std Deviation

0.0699

Cross-EU dispersion

Range

0.2818

0.2357 → 0.5175

Aggregation

Unweighted Arithmetic Mean

ISI I = (A1 I + A2 I + A3 I + A4 I + A5 I + A6 I) / 6

Composite Score Distribution

Distribution of ISI composite scores across the current release cohort (EU-27). Vertical bands indicate HHI classification thresholds.

Highly Concentrated

Moderately Concentrated

Mildly Concentrated

Unconcentrated

Reading the Index

The ISI measures external supplier concentration across 6 strategic axes using a Herfindahl-Hirschman Index (HHI) framework. Scores range from 0 (perfectly diversified) to 1 (total concentration on a single source).

≥ 0.50 — Highly Concentrated

Critical concentration on one or very few external suppliers.

0.25–0.49 — Moderately Concentrated

Significant concentration across a small number of sources.

0.15–0.24 — Mildly Concentrated

Moderate spread, but notable concentration remains.

< 0.15 — Unconcentrated

Broadly distributed across many external sources.

Country Rankings

Sortable rankings across the current release cohort (EU-27).

27 of 27 countries

Country	Composite	Rank	Δ Mean	Financial External Supplier Concentration	Energy External Supplier Concentration	Technology External Supplier Concentration	Defense External Supplier Concentration	Critical Inputs External Supplier Concentration	Logistics External Supplier Concentration	Classification
MaltaMT	0.5175	1/27	+0.1731	0.1400	0.3507	0.2055	1.0000	0.4087	1.0000	Highly Concentrated
CyprusCY	0.4682	2/27	+0.1238	0.1241	0.3477	0.2244	0.7485	0.4236	0.9411	Moderately Concentrated
IrelandIE	0.4280	3/27	+0.0836	0.1467	0.4647	0.5870	0.4489	0.3072	0.6137	Moderately Concentrated
DenmarkDK	0.4244	4/27	+0.0800	0.1240	0.4703	0.1500	0.7237	0.4363	0.6423	Moderately Concentrated
CroatiaHR	0.4043	5/27	+0.0600	0.2730	0.3513	0.1734	0.7465	0.5239	0.3580	Moderately Concentrated
FinlandFI	0.4021	6/27	+0.0577	0.1178	0.3627	0.1979	0.3896	0.5470	0.7973	Moderately Concentrated
SwedenSE	0.3987	7/27	+0.0543	0.1165	0.3272	0.1198	0.8811	0.1926	0.7551	Moderately Concentrated
AustriaAT	0.3825	8/27	+0.0381	0.1490	0.4558	0.2606	0.5851	0.3186	0.5259	Moderately Concentrated
ItalyIT	0.3739	9/27	+0.0295	0.1875	0.3078	0.1410	0.9206	0.2084	0.4778	Moderately Concentrated
SloveniaSI	0.3698	10/27	+0.0254	0.1192	0.4054	0.3574	0.6666	0.2230	0.4471	Moderately Concentrated
GreeceEL	0.3654	11/27	+0.0210	0.2008	0.3354	0.1627	0.5515	0.2220	0.7198	Moderately Concentrated
LuxembourgLU	0.3602	12/27	+0.0158	0.1146	0.3598	0.2002	0.6448	0.2230	0.6186	Moderately Concentrated
EstoniaEE	0.3433	13/27	−0.0011	0.1817	0.4394	0.2271	0.3556	0.3862	0.4699	Moderately Concentrated
BulgariaBG	0.3403	14/27	−0.0041	0.1605	0.3571	0.1520	0.8606	0.1484	0.3629	Moderately Concentrated
NetherlandsNL	0.3352	15/27	−0.0092	0.1211	0.3199	0.1253	0.9596	0.1302	0.3549	Moderately Concentrated
HungaryHU	0.3297	16/27	−0.0147	0.1222	0.3858	0.2254	0.5447	0.2341	0.4658	Moderately Concentrated
PortugalPT	0.3217	17/27	−0.0227	0.1830	0.3486	0.1977	0.4338	0.2596	0.5078	Moderately Concentrated
RomaniaRO	0.3186	18/27	−0.0257	0.2003	0.4055	0.2969	0.5635	0.1581	0.2875	Moderately Concentrated
CzechiaCZ	0.3180	19/27	−0.0264	0.1612	0.3808	0.1824	0.4841	0.1698	0.5295	Moderately Concentrated
PolandPL	0.2956	20/27	−0.0488	0.1331	0.3349	0.2085	0.4433	0.1653	0.4886	Moderately Concentrated
BelgiumBE	0.2880	21/27	−0.0564	0.1535	0.3079	0.2945	0.4473	0.1725	0.3521	Moderately Concentrated
GermanyDE	0.2679	22/27	−0.0765	0.1019	0.3291	0.0976	0.5827	0.2231	0.2730	Moderately Concentrated
LithuaniaLT	0.2654	23/27	−0.0790	0.1335	0.3375	0.2417	0.4023	0.1306	0.3469	Moderately Concentrated
SpainES	0.2609	24/27	−0.0835	0.1455	0.3019	0.1926	0.3809	0.1124	0.4324	Moderately Concentrated
LatviaLV	0.2470	25/27	−0.0974	0.1232	0.3652	0.1331	0.3408	0.1512	0.3682	Mildly Concentrated
SlovakiaSK	0.2364	26/27	−0.1080	0.1616	0.4000	0.2165	0.0000	0.1549	0.4855	Mildly Concentrated
FranceFR	0.2357	27/27	−0.1087	0.1004	0.3091	0.1200	0.3703	0.1612	0.3529	Mildly Concentrated

Scores are Herfindahl-Hirschman Index (HHI) values on [0, 1]. Higher = more concentrated external supplier structure. Below-mean values indicate less concentration; above-mean values indicate more. Δ Mean shows deviation from the cohort composite average.

Axis Registry

6 strategic axes of external supplier concentration, each composed of discrete data channels.

Axis 1

Financial External Supplier Concentration

Active

Concentration of inward banking claims and portfolio debt holdings across foreign creditor countries.

Ch. A: Banking Claims ConcentrationCh. B: Portfolio Debt Concentration

[Medium]BIS creditor coverage gap: non-BIS-reporting countries absent as creditors; concentration may be biased upward.

[Medium]IMF CPIS participation is voluntary; China does not participate. Portfolio debt concentration may understate true exposure.

[Low]Partial overlap between Channel A (bank claims) and Channel B (portfolio debt securities held by banks).

[Low]Croatia (HR) absent from Channel B (IMF CPIS). Score reduces to Channel A only.

Axis 2

Energy External Supplier Concentration

Active

Concentration of fossil fuel imports (gas, oil, solid fossil fuels) across supplier countries, volume-weighted across fuel types.

Ch. gas: Natural Gas Import ConcentrationCh. oil: Oil Import ConcentrationCh. solid_fossil: Solid Fossil Fuel Import Concentration

[Medium]Pipeline gas and LNG not separated. A country importing 50% pipeline gas from Russia and 50% LNG from multiple sources scores as if partially diversified.

[Medium]Re-exports and transit flows may distort bilateral attribution across all fuel types.

[Low]No price or contract-duration effects captured. Volume-based concentration only.

Axis 3

Technology External Supplier Concentration

Active

Concentration of semiconductor imports across supplier countries, with category-level decomposition.

Ch. A: Aggregate Supplier ConcentrationCh. B: Category-Weighted Supplier Concentration

[Medium]Re-export blindness: bilateral trade records shipping country, not country of origin.

[Low]Trade concentration does not capture domestic fabrication capacity.

[Low]HS 8542 at HS4 aggregate: integrated circuits not decomposed into subcategories.

[Low]Intra-EU trade included: EU partners appear as suppliers (by design).

[Low]Three-year window (2022–2024) may include pandemic-era distortions.

Axis 4

Defense External Supplier Concentration

Active

Concentration of major conventional arms imports across supplier countries and capability blocks.

Ch. A: Aggregate Supplier ConcentrationCh. B: Capability-Block Weighted Concentration

[Medium]SIPRI TIV is a volume indicator, not a financial value. Comparability across weapon types is approximate.

[Medium]SIPRI covers major conventional weapons only. Small arms, ammunition, MRO, and sustainment contracts are excluded.

[Low]Six-year delivery window (2019–2024) may include legacy contracts not reflecting current strategic posture.

[Low]Regex-based weapon classification may cause edge-case misclassification across capability blocks.

[Low]Countries with no bilateral SIPRI supplier entries are assigned score=0 (zero external concentration). This reflects licensed production, joint EU procurement, or domestic manufacturing.

Axis 5

Critical Inputs External Supplier Concentration

Active

Concentration of critical raw material imports across supplier countries, with material-group decomposition.

Ch. A: Aggregate Supplier ConcentrationCh. B: Material-Group Weighted Supplier Concentration

[High]Re-export and entrepot masking: bilateral trade records shipping country, not origin. 13 of 27 reporters source >50% from EU partners.

[Medium]Small-economy amplification: CY, MT, LU produce mechanically high HHI values due to low total import volumes.

[Medium]CN8 scope covers upstream materials only. Midstream processing and downstream products excluded. China's role understated.

[Low]Confidential trade suppression: Q-prefix partner codes excluded. May cause underestimation for some partners.

Axis 6

Logistics External Supplier Concentration

Active

Concentration of international freight across transport modes and bilateral freight partners per mode.

Ch. A: Transport Mode ConcentrationCh. B: Partner Concentration Per Transport Mode

[High]Entrepot/hub masking: NL and BE scores understate their systemic importance as continental freight hubs; countries trading through NL/BE have inflated partner concentration masking true origin.

[Medium]Geographic determinism: MT (Channel A HHI = 1.0), CY, and landlocked countries have structurally constrained scores reflecting geography, not policy choices.

[Medium]Maritime-energy overlap: maritime tonnage includes energy commodity transport, creating partial redundancy with Axis 3 (Energy).

[Medium]Tonnage blindness: all freight is treated equally per tonne regardless of commodity type; strategic commodity differentiation is absent.

[Low]No route/chokepoint data: the axis cannot detect Suez, Bosporus, or any physical corridor dependency.

Research & Publications

ISI Paper Series — methodological foundations, empirical results, and country-level analysis.

Paper 4Country Briefs

International Sovereignty Index (ISI) — EU-27 Country Brief Series (2024), Paper 4 (v1.0)

Drazsky, Sebastian, International Sovereignty Institute · March 2026

DOI: 10.5281/zenodo.18904016

View paper →

Paper 3Analytical Brief

International Sovereignty Index (ISI) — External Supplier Concentration in the EU-27: Empirical Findings (2024)

Drazsky, Sebastian, International Sovereignty Institute · February 2026

DOI: 10.5281/zenodo.18818748

View paper →

Paper 2Empirical Results

External Supplier Concentration in the EU-27: Empirical Results (2024)

Drazsky, Sebastian, International Sovereignty Institute · February 2026

DOI: 10.5281/zenodo.18764170

View paper →

Paper 1Methodology

The International Sovereignty Index: Construction, Methodology, and Computational Architecture

Drazsky, Sebastian, International Sovereignty Institute · February 2026

DOI: 10.5281/zenodo.18764227

View paper →

View all publications

Scope & Limitations

Not a risk score. The ISI quantifies concentration of external suppliers, not the risk or quality of those relationships.
Not a policy recommendation. High concentration may be economically rational in some contexts.
EU-27 scope only. Non-EU countries are not assessed.
Unweighted composite. The aggregation treats all axes equally. Domain weighting is outside scope.

See Methodology and Transparency for full details.

Sovereignty is structure.We measure it.

EU-27 Structural Exposure

Structural Outliers

Executive Summary

Composite Score Distribution

Reading the Index

Country Rankings

Axis Registry

Financial External Supplier Concentration

Energy External Supplier Concentration

Technology External Supplier Concentration

Defense External Supplier Concentration

Critical Inputs External Supplier Concentration

Logistics External Supplier Concentration

Research & Publications

International Sovereignty Index (ISI) — EU-27 Country Brief Series (2024), Paper 4 (v1.0)

International Sovereignty Index (ISI) — External Supplier Concentration in the EU-27: Empirical Findings (2024)

External Supplier Concentration in the EU-27: Empirical Results (2024)

The International Sovereignty Index: Construction, Methodology, and Computational Architecture

Scope & Limitations

Sovereignty is structure.We measure it.

EU-27 Structural Exposure

Structural Outliers

Executive Summary

Composite Score Distribution

Reading the Index

Country Rankings

Axis Registry

Financial External Supplier Concentration

Energy External Supplier Concentration

Technology External Supplier Concentration

Defense External Supplier Concentration

Critical Inputs External Supplier Concentration

Logistics External Supplier Concentration

Research & Publications

International Sovereignty Index (ISI) — EU-27 Country Brief Series (2024), Paper 4 (v1.0)

International Sovereignty Index (ISI) — External Supplier Concentration in the EU-27: Empirical Findings (2024)

External Supplier Concentration in the EU-27: Empirical Results (2024)

The International Sovereignty Index: Construction, Methodology, and Computational Architecture

Scope & Limitations

Sovereignty is structure.
We measure it.

Sovereignty is structure.
We measure it.