Australia and Japan Sign Contracts for $7 Billion Warship Deal

The Signing

On April 18, 2026, aboard the Mogami-class frigate JS Kumano docked in Melbourne, Australian Defence Minister Richard Marles and Japanese Defense Minister Shinjiro Koizumi signed contracts launching the largest defense export in Japan's postwar history [1]. The deal covers 11 upgraded Mogami-class stealth frigates for the Royal Australian Navy, valued at A$10 billion (US$6.5 billion) in initial acquisition costs, with total through-life spending projected at A$15–20 billion [3][15].

The signing capped a procurement process that began with the 2023 Defence Strategic Review, which concluded that Australia's existing naval force structure was inadequate for the deteriorating security environment in the Indo-Pacific [4]. It also marked a redemption for Japan's defense industry: in 2016, Australia rejected a Japanese submarine design in favor of a French one — a decision Canberra would itself reverse five years later when it scrapped the $90 billion AUD French Attack-class submarine program to pursue nuclear-powered boats under AUKUS [10].

What Australia Is Buying

The contract covers 11 frigates based on an upgraded version of the Mogami-class design, which Mitsubishi Heavy Industries has been building for the Japan Maritime Self-Defense Force since 2018 [14]. The Australian variant differs from the Japanese original in several ways:

• Displacement: 4,880 metric tons standard displacement, with a length of 142 meters [5]
• Weapons: 32-cell Mk 41 Vertical Launch System — double the 16-cell configuration on earlier Mogami variants — carrying ESSM Block 2 surface-to-air missiles and Naval Strike Missiles for anti-ship warfare [3]
• Anti-submarine warfare: Mk 54 lightweight torpedoes and MH-60R Seahawk helicopters [3]
• Point defense: SeaRAM close-in weapon system [3]
• Crew: 92 sailors and officers, compared to roughly 180 on the Anzac-class ships they replace [4][5]
• Range: Over 10,000 nautical miles, versus approximately 6,000 for the current Anzac class [2]
• Speed: 30 knots via a combined diesel and gas turbine (CODAG) propulsion system [5]

The Australian Strategic Policy Institute assessed the Mogami design as having 2.8 crew members per missile cell, compared with 3.4 for the US Arleigh Burke-class destroyer and 7.5 for the competing German Meko A-200 — a measure of automation efficiency that reduces long-term personnel costs [5].

The Money

The headline A$10 billion figure covers the acquisition of 11 hulls over roughly a decade. Naval News reported in April 2026 that the total program budget had grown to an estimated A$15–20 billion when factoring in sustainment, weapons integration, and infrastructure upgrades — up from an earlier A$7–10 billion range that the government initially cited [3]. Neither the Australian nor Japanese governments have published a per-unit cost breakdown.

For context, Australia's defense budget has risen from A$38.7 billion in fiscal year 2019-20 to A$58.2 billion in 2025-26 [8]. The frigate program represents a significant but not dominant share of that spending, though it sits alongside the far larger AUKUS submarine commitment.

Source: Australian Government Budget Papers

Data as of Apr 1, 2026CSV

Previous Australian naval procurements offer comparison points. The cancelled French Attack-class submarine program carried a price tag of A$90 billion for 12 boats — roughly A$7.5 billion per submarine — before Australia pulled out, having spent A$2.4 billion and eventually paying Naval Group a 555 million euro settlement [10]. The Hunter-class anti-submarine frigate program, covering six Tier 1 frigates based on a BAE Systems design, was separately plagued by cost overruns and an 18-month delay attributed to design immaturity [4].

Who Builds What, and Where

Japan — Hulls 1 through 3: Mitsubishi Heavy Industries will construct the first three frigates at its shipyards in Japan, with the first vessel expected to be completed by 2029 and operational by 2030 [8][14].

Australia — Hulls 4 through 11: The remaining eight frigates will be built at the Henderson Defence Precinct in Western Australia, with Austal — a Perth-based shipbuilder currently producing amphibious landing craft — expected to serve as the primary Australian constructor [3][9]. Construction at Henderson is slated to begin around 2030, contingent on upgrades to the precinct's infrastructure.

The Australian government has projected approximately 10,000 high-skilled jobs across the program's lifetime, concentrated in Western Australia [3][8]. MHI plans to host Australian engineers at its Japanese facilities during the initial build phase for welding and digital engineering training — a technology transfer arrangement designed to ensure competency before production shifts to Henderson [14].

Specific local-content requirements for the Australian-built hulls have not been publicly detailed. The Australian variant's integration of American and European weapons systems — rather than the Japanese Type 17 anti-ship missile and other domestic systems used on JMSDF Mogamis — suggests substantial work for Western subcontractors including Raytheon (ESSM), Kongsberg (Naval Strike Missile), and Lockheed Martin (combat management integration) [3].

The Capability Gap

The Mogami-class frigates will replace the RAN's eight Anzac-class frigates, which entered service between 1996 and 2006 and are approaching end of life [8]. The 2023 Defence Strategic Review identified a gap between Australia's aspirations as a regional naval power and its actual fleet size. At its August 2025 announcement, the government stated its intention to expand the RAN's major surface combatant fleet from 11 vessels to 26 over the coming decade [2].

Source: Australian Department of Defence

Data as of Apr 1, 2026CSV

The general-purpose frigates fill what defense planners classify as the Tier 2 role: patrol, presence, anti-submarine warfare, and local air defense. The six larger Hunter-class frigates occupy Tier 1, optimized for integrated air and missile defense alongside allied task groups. William Chou of the Hudson Institute characterized the Mogami as "a significant upgrade in numerous ways: it's larger, faster, has more range, is able to fire more missiles at once, and carries a stealth profile" [1].

The CSIS assessment noted that the capability gap is driven by specific Chinese actions: a November 2023 sonar incident against Australian divers, June 2024 water cannon attacks on Philippine vessels, February 2025 live-fire exercises in the Tasman Sea, and April 2025 military drills simulating Taiwan operations [4]. In February 2025, three Chinese warships operated in Australia's exclusive economic zone near the Tasman Sea, prompting alarm from both Australian and New Zealand defense officials [12].

The Critics' Case

Not everyone agrees that 11 new surface combatants are the right answer.

Sam Roggeveen of the Lowy Institute has argued that Deputy Prime Minister Marles's claim that the frigates will "secure our maritime trade routes" is overstated [6]. Australia's trade routes span vast oceanic distances — trade accounts for roughly 47% of GDP — and Roggeveen contends that no fleet of frigates can comprehensively protect them [6].

Source: World Bank Open Data

Data as of Dec 31, 2024CSV

More pointedly, Roggeveen and others aligned with his view question whether conventionally armed surface ships can survive in a high-end conflict against an adversary armed with modern anti-ship missiles. "Sea-skimming anti-ship missiles" and naval drones create survivability challenges that may not be manageable "without unacceptably high costs in self-defence weapons," Roggeveen wrote [6]. The Australian Naval Institute has published similar assessments noting that the proliferation of anti-ship missiles and uncrewed systems makes frigates and destroyers increasingly vulnerable [11].

Critics point to the 32-cell VLS as a specific limitation. Even at double the original Mogami configuration, 32 cells provide limited magazine depth against saturation attacks — a concern previously raised about the Hunter class as well, described by analysts as "taking a knife to a gunfight" in the threat environment of the 2030s [11].

Roggeveen has suggested that Australia would be better served investing in resilience — increased onshore storage of vital goods, expanded domestic manufacturing capacity, and accelerated renewable energy transition to reduce oil dependency — rather than additional surface combatants whose survival in a major war is uncertain [6].

Defenders counter that the Mogami's stealth profile, automation, and distributed lethality across 11 hulls offer a different kind of survivability. ASPI has argued that spreading firepower across a larger number of smaller, harder-to-detect platforms — rather than concentrating it in a few large warships — maximizes distributed lethality [5]. The CSIS analysis added that the Mogami's combat management system, designed from the ground up for Indo-Pacific threat environments, provides built-in advantages that adapted European designs do not [4].

AUKUS: Complement or Competitor?

The frigate program and Australia's AUKUS nuclear submarine commitment share a critical bottleneck: the Henderson Defence Precinct. Australia has pledged A$12 billion toward transforming Henderson into a facility capable of sustaining nuclear-powered submarines, with the total upgrade expected to cost A$25 billion over a decade [9]. The same precinct must accommodate construction of eight Mogami-class frigates beginning around 2030.

The AUKUS submarine timeline is already under pressure. Australia has acknowledged "challenges" in meeting its target of having an Australian-flagged nuclear submarine operational in the early 2030s [13]. The broader AUKUS plan envisions rotating US and British submarines through HMAS Stirling from 2027, selling Virginia-class boats to Australia from around 2030, and delivering the first Australian-built AUKUS-class submarine in the early 2040s [13].

Whether frigate construction at Henderson will crowd out submarine work depends on the scale and pace of the precinct's expansion. The government's position is that the A$12 billion infrastructure investment is sized to accommodate multiple concurrent programs [9]. But the compressed timeline — with both Mogami construction and submarine maintenance ramping up simultaneously — presents workforce and facility challenges that independent analysts have flagged but neither government has publicly quantified.

Satoru Nagao of the Hudson Institute framed the relationship differently: "If Australia buys Japan's weapons, Australia relies on Japan...such a situation will continue" [1]. The interdependence, he argued, strengthens the bilateral relationship in ways that reinforce rather than compete with AUKUS.

The Legal Architecture

The deal sits within a framework of bilateral defense agreements built over the past decade. The most significant is the Reciprocal Access Agreement, signed in January 2022 and entered into force on August 13, 2023 — Japan's first visiting forces agreement with any country other than the United States since 1960 [7]. The RAA provides standing legal arrangements for each country's forces to operate on the other's territory, covering entry and exit procedures, criminal jurisdiction, weapons handling, customs, and taxation [7].

The frigate contracts themselves were signed as a memorandum reaffirming both governments' commitment to the program's delivery, rather than as a treaty requiring separate parliamentary ratification [1]. Specific exit or penalty clauses have not been publicly disclosed. The 2023 National Defence Strategy explicitly called for strengthening ties with aligned partners, and Japan's Defense Minister Koizumi described the deal as being "of significant security importance to Japan" and enabling "enhanced joint operations and interoperability with both Australia and the United States" [2].

On the Japanese side, the deal represents the most consequential test of Tokyo's 2014 decision to relax its longstanding ban on military equipment exports. Before the Mogami contract, Japan's most notable defense export was a radar system sold to the Philippines [2]. Diet ratification was not required for the sale, but Japan's three principles on defense equipment transfer — revised in 2023 to further loosen restrictions — provide the domestic legal basis [14].

Beijing's Response

China has not issued a specific Foreign Ministry statement addressing the April 2026 contract signing, though Beijing has consistently characterized bilateral military groupings in the Indo-Pacific as "Cold War relics" [1]. China's Ministry of National Defense stated in December 2025 that military cooperation between allies in the region "should not target third parties, much less undermine regional peace and stability" [12].

Measurable escalation signals have accompanied prior Australia-Japan defense announcements. In February 2025, a Chinese naval task group — including three warships — conducted exercises in Australia's exclusive economic zone near the Tasman Sea, prompting monitoring by both Australian and New Zealand forces [12]. The CSIS timeline of Chinese coercive actions also includes the November 2023 sonar incident involving Australian divers and live-fire exercises in the Tasman Sea in February 2025 [4].

One analyst quoted by the South China Morning Post noted that Beijing's criticism of such arrangements "indicates that the Chinese are concerned about it," and that the frigate partnership "makes it harder for China to play Japan and Australia off against each other" [1]. The broader pattern suggests Beijing views the deal as part of a tightening web of Indo-Pacific security alignments that constrains its strategic flexibility, even if it has not yet responded with targeted trade measures or diplomatic demarches specific to this contract.

What Comes Next

The first Mogami-class frigate is expected off MHI's production line in 2029, with operational capability by 2030. The transition to Australian construction at Henderson will test whether the A$12 billion precinct upgrade can deliver capacity for both frigates and AUKUS submarine sustainment on overlapping timelines. The program's cost trajectory — already described by Naval News as having grown from A$7–10 billion to A$15–20 billion before a single hull is delivered — will face parliamentary scrutiny in a country with a recent history of defense procurement blowouts [3].

For Japan, the contract validates its post-2014 defense export strategy and deepens an industrial relationship that extends well beyond a single weapons sale. For Australia, the bet is that 11 stealth frigates — automated, long-range, and interoperable with both Japanese and American forces — can provide credible deterrence in waters where Chinese naval power is growing and the margin for miscalculation is narrowing.