HEAD TO HEAD
Japan vs United Kingdom
Verdict
Japan and United Kingdom are close to evenly matched, 50–50 on the Relative Advantage Index.
Japan leads on economic size (GDP) (52% of the combined total, $4.0tn) and active personnel (62% of the combined total, 247.0k), which United Kingdom offsets elsewhere.
1 factor — nuclear warheads — could not be scored because the figure is unpublished for at least one side. Those factors are excluded and the remaining weights renormalised, never substituted.
Factor by factor
| Factor | Japan | Share | United Kingdom | Weight |
|---|---|---|---|---|
Military spending SIPRI Milex | $62.2bn | 41%59% | $89.0bn | 33% |
Economic size (GDP) World Bank WDI | $4.0tn | 52%48% | $3.7tn | 27% |
Active personnel COW NMC | 247.0k | 62%38% | 150.0k | 20% |
Logistics & power projection OurAirports | 270 | 50%50% | 272 | 20% |
Shares are each side's portion of the combined total for that factor. Weights are renormalised across the factors both sides publish — see the methodology. Data read 2026-10-22.
