RUSI

RUSI's Arrow-3 depletion analysis remains the most-cited independent assessment of Israel's air-defence crisis: 81.33% depleted by 26 March 2026. As the conflict enters Day 60 with a diplomatic track underway, RUSI analysts have shifted toward the longer-term assessment framework: what a sustained Hormuz disruption means for European energy markets, whether Iran's three-phase sequencing reflects a genuine de-escalation intent, and what North Korea's NPT exit precedent implies for non-proliferation architecture. RUSI's Hormuz analysis has been picked up by Standard Chartered and other commodity desks as the primary London-based open-source intelligence on maritime risk.

The Royal United Services Institute (RUSI) is the UK's and the world's oldest defence and security think tank, founded in 1831 by the Duke of Wellington. Headquartered at Whitehall, London, it employs around 200 researchers and support staff and is led by Director-General Rachel Ellehuus, a former senior US Defense Department official who took up the post in January 2025. RUSI operates across five research groups: Land Warfare, Sea Power and Naval Policy, Air Power and Technology, Nuclear Policy, and International Security Studies. It publishes the RUSI Journal, RUSI Defence Systems, and an extensive series of occasional papers.

RUSI sits at the intersection of academic rigour and operational policy relevance. It hosts regular classified and unclassified roundtables attended by MoD officials, NATO planners, and parliamentary committees. Its Whitehall proximity means research outputs frequently feed directly into UK defence procurement debates and parliamentary evidence sessions. The Land Warfare and Modern deterrence programmes in particular have produced work that shapes frontline doctrine; RUSI researchers embed with Ukrainian forces and publish assessments of Russian tactics that are read by both MoD and allied militaries.

RUSI's reach extends across Lowdown topics: its drone campaign analysis is cited in drones-industry-defence coverage, its Hormuz maritime risk assessments feed into European energy markets analysis, and its cyber threat research is regularly cited on cyber-threats-and-defences. The institute has positioned itself as the authoritative UK voice on drone industrial capacity, naval mining doctrine, and the interplay between economic sanctions and military endurance.

RUSI has been among the most cited Western sources on the Russia-Ukraine war, with its embedded field researchers producing granular assessments of drone campaign effectiveness that other institutions cannot replicate. When Ukrainian SSU Alpha drones struck Samara, Tuapse, and Gorky , RUSI's analysis of refinery targeting logic and industrial attrition informed Lowdown's framing. The institute's work on Russian drone industrial capacity and Ukraine's counter-targeting doctrine has been the primary open-source basis for assessments of how long Russia can sustain its aerial campaign, particularly after refineries hit a 16-year low in output . RUSI analysts have also assessed the three-Ceasefire collapse pattern in U#16, providing methodological context for distinguishing tactical pause from strategic withdrawal in Russian positioning.

In July, Lowdown's assessment of Ukraine's shift to seaborne targets drew on RUSI's established shadow-fleet framework: once fixed refineries and terminals harden or exhaust as targets, pressure moves onto the tankers, since insurance, crewing and routing cannot be replaced as quickly as a damaged storage tank. Starboard Maritime Intelligence AIS data recorded a possible 55% drop in Sea of Azov tanker traffic between 30 June and 11 July, consistent with that pattern.

RUSI's Centre for Finance and Security contributed the most-cited independent assessment of the UK's May 2026 decision to ease sanctions on Russian-origin fuel products. Tom Keatinge, the centre's director, valued the permitted flow at $1.2-1.4bn a year at 2025 volumes and described the policy as an embarrassment for Downing Street, both for its substance and its poor communication. The analysis reflects RUSI's established specialism in the intersection of economic sanctions and security policy, a strand of work that sits alongside its military and maritime research and regularly feeds into FCDO and HM Treasury deliberations on sanctions architecture.