Methodology
ASEO is a relational country-year database: one row per African state per year, for all 54 states from 2000 to 2025 — a 1,404-row panel — joined to deal-level and dyad-level records beneath it. Every figure on this site derives from that structure; nothing is estimated or imputed.
Design & unit of analysis
The unit of analysis is the country-year. Underneath the panel, observations keep their natural grain: individual arms-transfer deals (5,293 records), recipient–supplier dyad-years (2,429), defence-cooperation dyad-years (925, with 66 partner states), presence records for 18 major installations by 8 external actors in 11 host states, and 15 UN/EU embargo regimes. Aggregates are computed upward from these grains, never entered by hand. Delivered volume totals 67,970 million SIPRI TIV over the period.
The design principle throughout: ASEO measures observable engagement — deliveries made, agreements signed, bases established, embargoes imposed — and leaves influence to the analyst's inference.
Data layers, sources & coverage
Seven open layers; coverage measured against the full 1,404 country-year panel
| Layer | Content | Principal open sources | Status / coverage in v1.0 |
|---|---|---|---|
| Arms transfers | Deliveries & orders of major conventional weapons (TIV) | SIPRI Arms Transfers Database | 5,293 deals · 2,429 dyad-years · 52 of 54 states |
| Military presence | Bases & confirmed deployments | Curated, cited open sources | 18 major installations · 8 actors · 11 hosts |
| Defence cooperation | Bilateral agreements in force | DCAD (Kinne 2018) + curated supplement 2011–25 | 925 dyad-years · 66 partner states |
| Arms embargoes | UN/EU regimes, scope-coded | UN Security Council · Council of the EU | 15 regimes, 2000–2025 |
| Armed conflict | Presence, intensity, fatalities | UCDP/PRIO ACD v25.1 · ACLED | 348 conflict country-years · 91.5% event coverage |
| Governance | Regime type, democracy indices | V-Dem | 99.2% of country-years |
| Economy & trade | GDP, military expenditure, small-arms customs value | World Bank · UN Comtrade (HS 93) | 82–94% by indicator · 70.9% (Comtrade) |
TIV = SIPRI trend-indicator value, a volume index of military capability — not a price. HS-93 customs value complements TIV: it captures small arms and ammunition, which TIV does not.
The External Military Engagement Index (EMEI)
The EMEI summarises how intensively outside powers engage a state militarily. It is a transparent, equal-weight composite of three observable components, each min–max normalised across the 54 states:
where ñarms is normalised delivered TIV, ñbase normalised foreign-base presence, and ñdca normalised defence-cooperation ties. Each release re-computes the index with perturbed weights and publishes the resulting sensitivity band; rankings that are not robust to the weighting are treated as ties. The EMEI is an index of engagement intensity, deliberately not an "influence score" — its components are inputs, and it makes no claim about outcomes.
Provenance on every record
Each record carries its source and a 1–3 confidence code. Hand-coded layers (base presence, embargo scope, post-2010 agreements) cite the public document or report they rest on.
No fabricated values
Of 80 candidate variables, each was graded by sourcing feasibility; the two with no defensible open source (troop / contractor headcounts, intelligence cooperation) are excluded rather than guessed. Missing means missing.
Validated releases
A four-layer validation suite — structure, referential integrity, value ranges, and totals cross-checked against SIPRI's published aggregates — must pass with zero failures before any release.
Reading the data
What is TIV, and why isn't it money?
SIPRI's trend-indicator value prices every weapon system against a common yardstick of military capability, so deliveries can be compared across suppliers, systems and years. It is a volume index: "TIV 500" means a certain quantity of capability changed hands, not that $500m was paid.
Why do the TIV and US-dollar rankings disagree?
They measure different trades. TIV covers major conventional weapons (aircraft, ships, armour, missiles); the customs value (UN Comtrade HS 93) captures small arms and ammunition. Egypt and Algeria lead the first; Nigeria and Kenya rank far higher on the second — both are true.
Why is a country blank on the map?
Blank means no recorded value for that measure — for arms, no recorded major-weapon deliveries (true for two of the 54 states over the whole period), not necessarily no weapons. Open sources under-count small and informal transfers.
Is the EMEI an influence score?
No. It aggregates observable engagement — arms, bases, defence pacts — into one comparable number. Whether engagement buys influence is precisely the research question ASEO leaves open; the index deliberately does not answer it.
Can I reuse the charts and data?
Yes. Everything on the site is published under the Creative Commons Attribution 4.0 International licence (CC BY 4.0): reuse, adapt and redistribute freely, with attribution and the DOI citation (https://doi.org/10.5281/zenodo.22234295). Every chart downloads as a citation-stamped PNG.
How often is the data updated?
On an annual cycle, within a quarter of SIPRI's spring Arms Transfers release. The current release covers 2000–2025 with sources current to 2025; site milestones are logged in the changelog.
Are the Outlook scenarios predictions?
No. The outlook page is the only forward-looking part of the site: three illustrative scenarios extrapolated from the observed record under explicit, transparent tilts. Analytical judgements, not forecasts — every other section reports observed figures only.
How should I cite the Observatory?
Ozturk, Yunus (2026). “African External Security Engagement Observatory (ASEO).” https://doi.org/10.5281/zenodo.22234295 — copy-ready formats, including BibTeX, are on the About page, and every profile carries its own suggested citation.
Limitations
Open sources carry gaps and reporting lags. Small island states and informal or illicit transfers are under-counted; Comtrade coverage depends on states' own customs reporting; ACLED coverage thins before 2010; and the presence layer records only major, well-documented installations. Scope of embargoes matters — several apply to non-government forces or sub-national territories only, and are coded as such rather than flattened to a national flag. Corrections and documented additions are welcome: y.ozturk@erdogan.edu.tr.