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In Japan we Trust? The Future of Anglo-Japanese Arms Collaboration

Growing initiatives point towards Japan being a key partner in future UK defence projects, reflecting a substantial shift and removal of obstacles in Anglo-Japanese collaboration.

May 2022 witnessed a spate of Anglo-Japanese announcements in the wake of Prime Minister Kishida’s visit to the UK. Prominent amongst them was the public reveal that British and Japanese companies – with their Governments backing – were in discussions to join forces in the development of their respective future fighter programmes – the Japanese FX and the British FCAS. Whilst details have yet to be finalised, any formal agreement would represent the largest Anglo-Japanese defence collaboration in history.

Such a project represents a substantial shift in previous UK dealings on Japanese defence procurement. For whilst there has been collaboration and pure sales in the past, Britain has historically been hesitant to commit fully to joint enterprises with the Japanese. Understanding ‘why’ offers insights into how the Anglo-Japanese relationship has evolved since 1945.


From Turbines to Nimrods – Previous Anglo-Japanese Defence Collaborations

Whilst they rarely interacted operationally in the Cold War period, a cash-starved British regularly attempted to sell its defence wares to the Japanese. Indeed, several notable successes were scored, with Rolls-Royce Adour engines, Olympus gas turbines and later Marine Spey engines all seeing successes in the 1970s (collectively netting the company around £80 million in revenue). Nor was the famous engine company the sole benefactor of UK defence sales to Japan: Ferranti managed to sell equipment for Japanese aircraft (some £7 million); International Military Services succeeded in pushing the FH 70 artillery system for the Ground Self Defence Forces (around £60 million); and the BAe 125-800 – reportedly one of the largest contracts secured with the Japanese post-1945 by a non-US firm – made its way into Japan in 1991. While mostly license-build agreements, they represented successful penetrations of a market known for favouring indigenous builds or buying American.

Nor were these simply commercial operations. Successive British Governments pushed defence sales both at the Ministerial and Official level. This included flying Prince Phillip in a BAe 146 during his World Wild Life tour in Japan; and pestering Japanese Ministers during visits about the advantages of the Nimrod Maritime Patrol Aircraft – as Ted Heath, Harold Wilson and Margaret Thatcher all did. Across the late twentieth century, then, many British sales attempts came directly from the top.

Nonetheless, the first real attempts at proper Anglo-Japanese defence collaboration was kickstarted in 1963 with the visit of Takeshi Kitamura – then Secretary-General of the National Defence Council – to the UK. Whilst welcoming, British officials were not initially sure what to make of the requested visit. However, after four hours of meetings with the then Ministry of Defence (MoD) Permanent Under Secretary Sir Robert Scott, it became clear that “he was much less interested in our assessment of politico-military situations in different parts of the world than in exploring the possibilities of specific Anglo-Japanese co-operation in defence matters.”

In particular, Kitamura was hopeful for a joint R&D programme with the British, noting in a meeting with MoD officials that Japan spent “practically nothing” on research, and that he was “very anxious to reduce the time which it took to get weapons into service.” It would be a start-from-scratch approach for the Japanese side, but Kitamura did float the idea of Japanese scientists training in the UK. For the British, there was cautious optimism of lucrative contracts being secured and the lessening of the defence burden being achieved.


Failing to Trust – Reasons for Failure

Whilst collaboration was far from superficial, there did remain substantial obstacles to full British collaboration with the Japanese, particularly outside of pure sales. The core concerns for successive British Governments focussed ultimately on matters of security.

Indeed, though the Kitamura collaborative project fell down for multiple reasons, the Japanese’s inability to sign the Memorandum of Understanding for Collaboration on Research and Development, which the British had used as a template with other European nations, was a major obstacle. The Memorandum of Understanding in question required security guarantees in order to prevent the dissemination of intellectual property illegally. During initial scoping conversations, Sir Scott had been clear that this was non-negotiable for the British, to which Kitamura admitted it may cause constitutional difficulties due to Japan’s lack of an Official Secrets Act equivalent. Whilst the Americans reportedly remained satisfied without this legislative shield, for the British it remained a sticking point in any possible collaborative projects.

This lack of trust in Japanese internal security also extended to the potential sales of technologically advanced weapons. Two particular instances saw the Navy Department – through the Arms Working Party – veto potential sales to Japan of both Redtop air-to-air missiles and Tigercat surface-to-air missiles in 1966; and Sea Dart surface-to-air missiles in 1967 on “the grounds that Japanese security is inadequate.” While the Sea Dart was eventually cleared, concerns remained.


All in this Together – Anglo-Japanese Defence Collaboration Today

Concern had slowly dissipated by the 1970s and 1980s, but the issue of Japanese internal security remained an issue for not just the British. As late as 2020, Mitsubishi confirmed it may have lost sensitive defence-related data in a cyber attack; while the leaking of data in 2007 on missile defence systems saw the US Commander of forces in Japan publicly expressing exasperation. Moreover, the British were further hampered by Japanese legislation forbidding Japanese firms from entering into overseas partnerships to produce defence equipment except to meet the exclusive requirements for the Japanese Defence Agency. However, as the 21st century rolled in, both these issues were tackled head on.

On matters of security, a major step was taken in 2012 when the Japanese Ministry of Defence (JMoD) and British MoD signed a joint memorandum on defence co-operation with, which described how “the ministries will uphold rigorous standards to protect information exchanged between them and that neither country will pass the information on to a third country without the other ministry’s consent.” The same year, the Japanese Diet alleviated fears of not possessing an anti-espionage law by passing a bill which protected classified information by strengthening penalties.

This was reinforced a year later by a formal agreement between the UK and Japan which outlined “the protection of secrets shared at the governmental level, rather than merely at the ministerial level.” It is perhaps no coincidence that both the Anglo-Japanese agreement on joint development of Chemical, Biological, Radiological and Nuclear (CBRN) suits and the announcement of plans to collaboration on missile technology – later known as the Joint New Air-to-Air Missile (JNAAM)were announced in 2013 and 2014 respectively.

Moreover, perhaps one of the biggest signs of opening opportunities in Anglo-Japanese collaboration was the announcement on 27th May 2022. Whilst security issues had remained an issue for the British, the matter of export markets and the limitations presented by Japanese legislation in this endeavour equally damaged prospects of big-ticket collaborative projects. This was promptly rectified on 27th with the announcement that the Japanese Government plans to allow the export of fighter jets, missiles and other arms to 12 selected countries, even if they are not developing jointly that specific weapon system. Obviously for the British, who have an eye on potential exports of the FCAS programme, this only sweetens the possibility of bringing the Japanese deeper into the programme.



Anglo-Japanese defence collaboration has come a long way since the tentative steps of the early 1960s. However, unlike these older projects, FCAS, JNAAM etc. promise to be far deeper – not to mention more complicated and expensive – in terms of Anglo-Japanese collaboration. With issues of British trust and Japanese legislative limitations slowly overcome, the future for defence collaboration remains optimistic, as long as momentum at the Ministerial level can continue.

In this story

William Reynolds

William Reynolds

Research Associate

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