Glossary

These sites assume no prior specialism. The first mention of any term defined here is linked automatically in every article.

AGSI+

Gas Infrastructure Europe's Aggregated Gas Storage Inventory: the daily record of how full European gas storage is.

AUKUS Pillar 2 also: Pillar 2

The non-submarine half of AUKUS: hypersonics, undersea autonomy, quantum, electronic warfare and AI, plus the export-control reform needed to make them shareable.

BGP

Border Gateway Protocol: how networks announce which blocks of the internet they can reach. Mis-announcements — accidental or not — reroute traffic.

chokepoint also: chokepoints

A narrow sea passage through which a disproportionate share of trade must pass, and where a small disruption produces a large effect.

CVE also: CVEs

Common Vulnerabilities and Exposures: the identifier scheme that gives each publicly disclosed software flaw a stable name.

EEZ also: Exclusive Economic Zone

Exclusive Economic Zone: the area up to 200 nautical miles from a coastal state's baselines in which it holds sovereign rights over resources — not sovereignty over the water itself.

first island chain

The archipelagic line running from the Japanese home islands through the Ryukyus, Taiwan and the Philippines to Borneo. Usually drawn as a barrier from the mainland's perspective.

geostationary orbit also: GEO

A circular orbit at 35,786 km over the equator, where a satellite's period matches Earth's rotation so it appears fixed in the sky. Slots are finite and coordinated.

grey zone also: gray zone

Coercion deliberately kept below the threshold that would trigger an armed response: coast guard pressure, militia fleets, cable interference, lawfare.

KEV also: KEV catalog,Known Exploited Vulnerabilities

CISA's Known Exploited Vulnerabilities catalog: the list of vulnerabilities with evidence of active exploitation. Listing carries a remediation deadline for US federal civilian agencies.

low Earth orbit also: LEO

Orbits below roughly 2,000 km: short revisit times, low latency, and where nearly all catalogued debris sits.

military expenditure also: milex

Government spending on armed forces and their activities, on the SIPRI definition. Commonly quoted as a share of GDP.

SATCAT

The satellite catalogue: the register of tracked objects in Earth orbit, including payloads, spent rocket bodies and debris.

SDN list also: SDN,Specially Designated Nationals

The US Treasury's Specially Designated Nationals and Blocked Persons list: the core US sanctions designation instrument.

UNCLOS

The UN Convention on the Law of the Sea: the treaty framework defining territorial seas, EEZs, and rights of transit passage.