For Sir Simon McDonald, former head of Britain’s Foreign Office, the country is ‘at the end of its game.’ In an interview published this month the retired career diplomat dismissed the ability of Britain and countries with similar capacities to shape international affairs. As the interviewer Harry Lambert observed, Sir Simon thought little of the idea that Britain can act collectively alongside other ‘middle powers’. Working with others was, to his mind, ‘nice’ but ‘insignificant,’ since collective action with countries such as Australia or Canada would not make the international weather. Outside the European Union, he believed, Britain’s limited material means left the country with one single strategic choice for relevance: to follow the United States.

Ironically,  Japan, which according to McDonald is faring better than Britain, regularly invites similar views. In a recent commentary in the New York Times, Jennifer Lind noted three possible options. Tokyo could continue to ‘pass the buck’ and hope that reliance on the US for its security is sufficient. Or it could terminate its relationship with Washington and seek some form of appeasement with China. Or, it could build upon the decision taken in December to increase its defence budget, and grow military spending even more to play a role as an indispensable ally for the US.

Both views share a problematic assumption. They draw upon a worldview in which a country’s capacity to influence and shape international security rests overwhelmingly, if not exclusively, on sheer sovereign, hard power. Without that, one is relegated to the status of a second tier actor — a middle power, and more defence spending is the only answer.

Such an assumption misses, however, what middle powers like Britain and Japan have proven to do best. They develop strategies to leverage tools of statecraft, both soft and hard. They specifically apply military power in ways that underwrite their commitment to it. They prefer collective forms of action in an effort to share costs. Military power is only one component of strategy for the middle powers.

British and Japanese grand strategies are informed by their character as maritime states — a point often missed. They both place the ocean at the centre of their respective approaches to the international order. Whether one looks at achieving a free and open Indo-Pacific or preserving undersea cables, physical and digital maritime connectivity are key to prosperity. This, in turn, informs their actions in three crucial ways.

First, Britain and Japan have consistently acted to corral support for the maritime order. In 2014, when coercion was emerging as a preferred course of action in disputes in the China Seas, then-Prime Minister Shinzo Abe took the stage at the Shangri-La Dialogue to stress the need for respect of the core tenets of the United Nations Convention on the Law of the Sea (UNCLOS). Two years later, Japan and Britain shaped the G7 agenda around these concerns.

Deeds have followed words. For more than a decade, Japan joined counter-piracy activities in the Gulf of Aden, taking on a military leadership role for the first time since the Second World War. Britain too, despite commitments in Afghanistan and Iraq, upped its role as a guardian of the maritime order. In 2018, as maritime disputes in the China Seas escalated, Britain became the first — and, at present, the only — country other than the US to challenge China’s maritime claims to the disputed Paracel islands.

Second, both countries have championed collective prosperity. Since the announcement of the Free and Open Indo-Pacific initiative in 2016, Japan has strategically reviewed its foreign aid to foster quality infrastructure, connectivity, and capacity-building in countries like the Philippines, Vietnam, and the South Pacific islands. It has also led to the conclusion of the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, with the UK becoming the first European country to join in 2023.

The UK has led in the collective action to increase marine environmental protection and poverty reduction. Britain’s £500 million Blue Planet Fund calls for the protection of at least 30 per cent of the global ocean by 2030, through the 30by30 initiative, and it supports efforts in stopping plastic pollution through the Commonwealth Clean Ocean Alliance. The sustainability of the ocean represents an existential threat to many archipelagic and island nations.

This leads to a third observation. Neither Britain nor Japan underestimate the challenge of state actors, from China and Russia to North Korea and Iran, to the global order. On the contrary, both countries understand how the core challenge is taking place at sea, and have been committed to a recapitalisation of their maritime power to meet what Britain’s First Sea Lord called ‘another dreadnought moment.’

Such a transformation though, is not just about budget allocations. The signing of a Reciprocal Access Agreement in 2023 indicated a new way of thinking about operating globally with close partners. The AUKUS and GCAP agreements, respectively focusing on the development of a nuclear-powered submarine capability for Australia and a next-generation fighter jet for Britain, Japan and Italy, reflect an ambition to develop increasingly cutting-edge capabilities. Changes in Australia’s defence posture, and its greater appetite for cooperation with Japan and Britain also reinforces the notion that maritime middle powers are leaning on each other.

It should come as no surprise, therefore, that this week Prime Ministers Rishi Sunak and Fumio Kishida offered the strongest rebuttal to dismissive views of middle powers yet. As the latter hosted the G7 summit in Hiroshima, the former articulated, together with his host, why Japan and Britain together are indispensable to the international order. They signed the Hiroshima Accord, an ambitious pathway to enhance bilateral cooperation in areas of the economy, resilience, and security. The accord reflects a common maritime worldview, one in which the Euro-Atlantic and the Indo-Pacific are indivisible components of one interconnected space.

Britain and Japan send a powerful message. We live in a maritime century. Middle maritime powers by their own character pursue solutions that do not focus purely on military might. They pursue capabilities to reassure partners and signal intent to opponents. In so doing, countries like Britain and Japan become indispensable powers for the international order, offering their citizens more than just survival in a struggle for a balance of power.