Japan's EEZ reversal: how the world's last defender of Mare Liberum became an enclosing state

Posts 052 and 053 traced the domestic governance history of Japan's fisheries: how the 1741 spatial principle became the 1949 cooperative rights system, and how that system's structural failure was partially addressed by the 2018 reform. Both posts examined governance from the inside — the domestic institutional configurations that produced the outcomes they described.

Post 054 examines the same history from the outside: Japan's relationship to the international legal architecture governing who owns the sea. It is structured around a specific historical mystery that the EEZ source materials identify as the central analytical question: why did Japan, which had been the world's most committed defender of the doctrine of freedom of the seas (Mare Liberum), eventually become one of the strongest advocates of the very 200-mile exclusive economic zone that it had fought most vigorously to prevent?

The answer is one of the most precise illustrations in this blog's arc of how external forcing functions can reverse institutional positions that decades of internal logic have made seemingly immovable.

The starting point: a 3-mile territorial sea as passive defence

Japan's first modern maritime law — the 1870 declaration of a 3-mile territorial sea — was not a resource management decision. It was a security decision driven by a specific and immediate threat perception: the Franco-Prussian War had broken out in Europe, and the Meiji government feared that the naval conflict might extend to Asian waters, with French and Prussian vessels fighting within sight of the Japanese coast.

The 3-mile standard was not Japan's invention. It was the international norm derived from the "cannon shot rule" — the maximum range of shore-based artillery, which in the eighteenth century was approximately three nautical miles. The new Meiji government adopted it because it was the recognised international standard, and because what Japan needed in 1870 was not a resource management framework but a legal buffer: a zone within which the combat activities of foreign navies could be legally prohibited.

In GMM terms, Japan's first maritime governance was entirely Layer A-defensive in character: not managing resources, not claiming economic rights, but establishing the minimum legal perimeter required to maintain neutral territorial integrity during a European conflict in which Japan had no stake. The 3-mile standard was maintained, with international support from the major naval powers (the US, UK, and France, whose distant-water interests it served), for the next 107 years.

The Meiji expansion and its human cost: the 1926 crab boat disaster

While the territorial sea remained at 3 miles, the scope of Japan's actual fishing operations expanded across the entire Pacific and beyond. The driving force was the same population-protein equation that Post 052 identified: rapid urbanisation, rising living standards, and a growing national population that demanded more marine protein than inshore fisheries could supply. The Japanese government's response was to subsidise and enable the expansion of distant-water fishing fleets into the North Pacific, the Bering Sea, and the waters surrounding Kamchatka and Sakhalin — areas that were, under the Mare Liberum doctrine, legally open commons accessible to any nation's vessels.

The 1907 Russo-Japanese Fisheries Agreement and the 1927 Soviet-Japanese Fisheries Treaty gave Japan legal access to Russian coastal waters — a remarkable diplomatic achievement that sustained the North Pacific fishing industry for decades. But the RSM configuration of this industry carried a structural failure that the 1926 crab boat disaster made impossible to ignore.

In September 1926, the factory ship Chichibu Maru, operating in waters off the Kamchatka Peninsula, was struck by a storm. Of the 376 crewmen aboard, 181 died — nearly half the total. The conditions they had been working under were documented in survivor accounts and investigated in press reports: extreme cold, inadequate safety equipment, production quotas prioritised above crew welfare, and labour relations that left workers with no mechanism to refuse unsafe assignments.

Three years later, the proletarian author Kobayashi Takiji published The Crab Cannery Ship — a fictional account of these conditions that became one of the most widely read works of Japanese political literature. The novel's analytical significance for Post 054 is not its literary quality but its CPM function: it created a national narrative about the human cost of the "Mare Liberum expansion" model that had previously been invisible to the urban population that consumed its products. The RSM dysfunction — capital extracting maximum output from labour with no functioning correction loop — was made visible to the Auditor function of the public. The political consequences were modest at the time, but the narrative established that the costs of the distant-water expansion model were not only borne by the fish stocks being depleted.

The postwar configuration: the MacArthur Line and the Syngman Rhee Line

The 1945 defeat produced the most complete external reset of Japan's maritime governance in the modern period. The GHQ's MacArthur Line — a series of exclusion zones around Japan's coastline beyond which Japanese fishing vessels were prohibited from operating — compressed Japan's fishing operations from global to near-coastal in a single administrative action. The practical effect was that Japan's distant-water fleets, which had been operating in the North Pacific and far beyond, were confined to the waters immediately adjacent to the Japanese islands.

The MacArthur Line's CPM effect was significant and lasting. The perception it created — "our right to fish the open ocean has been arbitrarily taken from us by external power" — established a narrative framework for Japanese fisheries policy that would shape institutional responses for the next three decades. When the San Francisco Peace Treaty of 1952 restored Japan's right to distant-water fishing, the institutional memory of the MacArthur Line made any subsequent restriction of maritime access — however legally grounded — feel like a repetition of wartime encirclement.

This narrative framework was immediately tested. In 1952, the same year the MacArthur Line was lifted, the South Korean government under President Syngman Rhee unilaterally declared an exclusive maritime zone extending up to 200 nautical miles from the Korean coast — cutting directly through waters that Japanese fishing vessels had historically worked and were now legally entitled to re-enter. Japanese fishing boats that crossed the Rhee Line were seized; some crews were imprisoned; some vessels were fired upon.

The Syngman Rhee Line had a double CPM significance: it was experienced as both a concrete economic harm (Japanese fishermen losing access to productive grounds) and as an ideological threat (a precedent for the kind of unilateral maritime enclosure that Japan had been arguing was inconsistent with international law). Japan's institutional response was to intensify its diplomatic opposition to any extension of territorial sea limits — not just by South Korea but by any nation — because accepting such extensions as legal would validate the Rhee Line's logic.

The 12-mile debate: Japan as the world's most committed defender of Mare Liberum

Through the 1950s and into the 1960s, an international movement gathered momentum to extend the standard territorial sea from 3 miles to 12. The argument was that the 3-mile limit had been established when cannon range was the practical standard for coastal defence; modern military technology made the 3-mile zone meaningless as a security perimeter, and 12 miles better reflected the actual range within which a coastal state had legitimate interests.

Japan opposed this extension with a consistency and intensity that stands out in the diplomatic record. The reason was straightforwardly RBM: Japan was, by the 1960s, the world's largest distant-water fishing nation. Every country that extended its territorial sea by 9 miles was adding 9 miles to the exclusion zone surrounding its coast — and since Japan's fishing vessels operated in waters adjacent to many countries' coasts, every 12-mile extension represented a reduction in the area of legally accessible public sea that Japanese fleets could work.

In GMM terms, Japan's governance was committed to a specific model: supply Japan's protein needs by extracting them from other countries' adjacent waters under the legal protection of Mare Liberum. Challenging this model was not merely economically threatening; it was institutionally unacceptable because the entire architecture of the distant-water fishing industry — the subsidies, the vessel construction programmes, the international fishing agreements, the processing infrastructure — was built around it. The Auditor function (international law trends, stock depletion evidence) was generating signals that the model was becoming unsustainable; the production loop (distant-water industry interests and the political constituency they represented) was generating overwhelming pressure to maintain it.

The Soviet 200-mile declaration and the mechanism of the reversal

The CPM mechanism that broke Japan's commitment to Mare Liberum is one of the most instructive examples in this blog's arc of how the same external forcing function can produce opposite institutional responses depending on which side of the boundary you are on.

In 1976, the Soviet Union declared a 200-mile fishing zone around its coastline. This was a direct, immediate, and economically devastating blow to Japan's North Pacific fleet — the most productive component of Japan's distant-water industry. Japanese fishing vessels that had been legally operating in what was now Soviet-claimed water were suddenly required to obtain Soviet permission or withdraw. The scale of displacement was enormous: the North Pacific had been the primary source of Japan's distant-water catch for decades.

The displacement itself was not what reversed Japan's institutional position. What reversed it was what happened next. The Soviet fleet — which had previously been operating in North Pacific waters that were now within its own 200-mile zone — needed somewhere else to go. It came to Japan's near-shore waters, which under the still-prevailing 3-mile territorial sea regime were legally open commons. Soviet factory ships and trawlers began operating within sight of the Japanese coast, harvesting the inshore and nearshore stocks that Japanese coastal fishing communities depended on.

Korean fleets, similarly displaced from waters they had previously worked near the Soviet coast, followed the same logic. Within months, Japan's coastal fishing communities were experiencing in their own near-shore waters precisely what Japan had been arguing was illegal for South Korea to impose through the Rhee Line: massive foreign fleet operations destroying local fishing livelihoods.

The RSM that now operated was completely different from the one that had been defending Mare Liberum. The coastal fishermen whose grounds were being devastated were not the distant-water interests that had been the primary constituency for the open-seas doctrine. They were a separate and in some ways politically more potent constituency: geographically dispersed across every coastal prefecture, represented in every local assembly and every national Diet election district, and experiencing an immediate and undeniable destruction of livelihood that no diplomatic abstraction could mitigate.

Their political pressure was directed not at the Foreign Ministry or the Fisheries Agency bureaucrats who had been managing the Mare Liberum position, but at their local representatives — the Diet members from coastal constituencies who could not explain to their voters why the Japanese government was defending the legal right of Soviet factory ships to destroy local fisheries. The belonging pressure and survival pressure that CPM identifies as the most powerful cognitive forces were operating simultaneously, on a large number of voters, in a direct and immediate way. The institutional position collapsed within months.

1977: the Fisheries Waters Provisional Measures Act

In 1977, Japan enacted the Fisheries Waters Provisional Measures Act and simultaneously extended its territorial sea to 12 miles — doing in a single year what it had spent two decades opposing in international negotiations. The 200-mile fisheries zone the act created was immediately effective against Soviet and other foreign fleets. An exclusion zone that Japan had argued was inconsistent with international law when South Korea applied it in 1952 became Japan's own legal instrument in 1977.

The GMM analysis of this transition reveals the specific mechanism of the reversal. Japan's pre-1977 governance model was "extract supply from other countries' adjacent waters." Japan's post-1977 governance model was "manage supply within our own adjacent waters." The external forcing function — Soviet 200-mile declaration displacing fleets into Japanese near-shore — had made the first model unworkable by simultaneously removing Japan's access to the supply it depended on and enabling the destruction of the inshore supply that the domestic coastal industry operated on.

The transition was also incomplete in a revealing way: the 1977 law initially excluded Chinese and Korean vessels from its 200-mile restrictions, out of diplomatic sensitivity toward Japan's most immediate neighbours. The domestic political logic that had driven the law — coastal fishermen's survival pressure — continued operating after its enactment. By 1983, the exclusions had been eliminated, and the Japanese EEZ applied uniformly. The political pressure from coastal constituencies that had reversed Japan's international position on maritime law continued to push the implementation of that position to its logical conclusion.

UNCLOS and the delayed ratification: GMM silo failure

Japan's 1996 ratification of the United Nations Convention on the Law of the Sea (UNCLOS) — signed in 1982 but ratified fourteen years later — reveals a different structural failure: the bureaucratic silo problem in integrating international legal obligations across multiple ministries.

UNCLOS is not simply a fisheries law. It governs territorial sea limits, continental shelf rights, deep-sea mining, navigation rights, environmental protection obligations, and the resolution of maritime boundary disputes. Its implementation required coordinated action across the Foreign Ministry, the Fisheries Agency, the Ministry of Transport, the Japan Coast Guard, the Japan Maritime Self-Defence Force, and the Environment Agency. Each of these agencies had different primary interests in the UNCLOS provisions relevant to their domain, and none of them had clear authority to coordinate the others.

The RSM failure was the Integrator deficit: there was no institutional actor with the mandate and the capacity to orchestrate the inter-agency implementation that UNCLOS ratification required. The fourteen-year ratification delay was partly a product of genuine technical complexity, but it was primarily a product of bureaucratic fragmentation: each silo waiting for resolution of the issues relevant to its domain before committing to ratification, with no centralised decision mechanism capable of accepting the trade-offs that ratification required.

The 2007 Basic Ocean Law and the creation of the Headquarters for Ocean Policy under the Cabinet Office was the institutional response to this silo failure — an attempt to create the Integrator function that UNCLOS implementation had revealed was absent. The law established a ten-year ocean policy plan and gave the Cabinet Office the coordinating authority that individual ministries had been unable to provide. It was a belated but structurally significant correction to the RSM deficit that the UNCLOS ratification delay had exposed.

The ALPS treated water issue and the limits of legal governance

The ongoing dispute over the release of ALPS-treated water from the Fukushima Daiichi nuclear plant into the Pacific Ocean is the most visible current illustration of the structural tension that runs through Japan's entire EEZ governance history: the gap between what the international legal framework permits and what domestic stakeholder communities are prepared to accept.

The IAEA's 2023 safety review concluded that the treated water release met international safety standards. The international legal framework governing ocean discharge — both UNCLOS and the London Protocol — provided no basis for prohibiting it. Japan's national government made the political decision to proceed. And Japan's fishing cooperatives maintained their formal opposition, passed repeated resolutions against the release, and sued the government.

The CPM mechanism at work is precisely the one that Post 053's red tide crisis had illustrated in a different context: a regulatory determination about scientific safety does not resolve the CPM narrative about community risk and economic survival. The fishing cooperatives' narrative — "we have been bearing the reputational costs of Fukushima for twelve years; this release will extend those costs indefinitely, and we have not consented to bear them" — is not defeated by the IAEA safety assessment. The two narratives operate on different dimensions: one is a scientific claim about contamination levels, the other is a political claim about who bears the costs of governance decisions made by others.

Japan's EEZ governance has matured significantly from the 1870 cannon-shot rule through the 1977 forced conversion and the 2007 ocean policy integration. What it has not resolved is the structural gap between international legal frameworks (which address state-level rights and obligations) and the community-level social licence that makes governance of those rights and obligations practically operable. The ALPS water dispute is the current manifestation of a gap that has been present since the Meiji Fisheries Act encoded traditional community rights in modern property law.