Amidst rising regional threats and global uncertainty, Japan unveils its plan to procure two advanced weapons systems to fortify its defense posture and ensure peace and stability.

Japan’s Ministry of Defense (MoD) has recently unveiled its plan to procure two Aegis System Equipped Vessels (ASEVs) as a replacement for the now-defunct land-based Aegis Ashore ballistic missile defense (BMD) system. These new sophisticated military assets will be equipped with advanced radar systems, missile launchers, and enhanced interception capabilities.

This article delves into the specifications and features of these vessels, the controversies surrounding their development, and the significance of their introduction to Japan’s maritime defense strategy.

What is ASEV?

According to the defense white paper, the ASEVs are naval ships fitted with advanced warfare technologies, including Lockheed Martin’s SPY-7 radar system, which was originally intended for the Aegis Ashore system. The version of the Aegis system on the ASEV, known as J7.B, has been modified to integrate the SPY-7 radar into Baseline 9 (BL9).

The configuration of the main armament on the ASEV is similar to Japan’s Maya-class Aegis-equipped destroyers, featuring an Mk-45 (Mod.4) 5-inch/62-caliber (127mm) main gun. However, the topside area above the bridge of the ASEV has drawn comparisons to Australia’s Hobart-class Aegis-equipped air warfare destroyers due to its Aegis radar arrays.

The sophisticated vessels are expected to boast an impressive 128 Vertical Launch System (VLS) cells, providing enhanced interception capabilities against both conventional ballistic missile warheads and hypersonic glide vehicles (HGVs). This marks a significant improvement compared to the 96 cells of Mk41 VLS on the Maya-class destroyers.

Controversies and Revisions in the Construction Plan

The original plan for the ASEVs had drawn criticism, as the ships were initially designed to be around 210 meters long, 40 meters wide, and have a standard displacement of 20,000 tons. Critics argued, as reported by Naval News late last month, that the large size and lack of maneuverability would burden the Japan Maritime Self-Defense Force (JMSDF) and taxpayers.
In response to these concerns, the defense ministry has revised the ship’s construction plan to make it smaller and add anti-submarine capabilities.

The MoD has also allocated significant funding for the procurement of the ASEVs, with a total budget of 220.8 billion yen ($1.58 billion). Additionally, two local companies, Mitsubishi Heavy Industries (MHI) and Japan Marine United Corporation (JMU), have been awarded contracts for the design work and construction of the vessels, respectively.

Significance and Timeline

The introduction of the ASEVs represents a crucial step in Japan’s effort to enhance its missile defense capabilities and address regional security challenges posed by neighboring countries. With tensions escalating in the East China Sea and the Korean Peninsula, Japan aims to strengthen its defense posture and ensure the safety of its citizens.

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As a quick recap: In recent events, North Korea fired two ballistic missiles into the sea off its east coast on July 24, followed by several cruise missiles on July 21 and two ballistic missiles on July 19. These launches coincided with the visit of a U.S. nuclear-powered submarine at a South Korean naval base, adding to regional tensions. Additionally, North Korea warned that deploying U.S. aircraft carriers, bombers, or missile submarines in South Korea could trigger its use of nuclear weapons.

Furthermore, the area has witnessed increased naval activity by China and Chinese-Russian naval maneuvers, including missile firings and interceptions, sending strong signals to Japan and the U.S. A visit by the Russian defense minister to North Korea, along with coordinated actions by Russia and China, has raised concerns about the region’s stability and security. These developments pose significant challenges to peace and stability in the Korean Peninsula and surrounding waters.

Japan’s MoD targets commissioning the first ASEV by the end of March 2028, with the second vessel to be inducted by March 2029. These advanced Aegis-equipped ships are expected to play a vital role in Japan’s maritime security strategy, acting as a deterrent against potential threats and bolstering the country’s ability to protect its territorial integrity and national interests.

Japan’s Defense in 2023: Navigating a New Era of Crisis

The Defense of Japan 2023 white paper presents Japan’s defense strategy amidst a turning point in global history. Again, the international community has faced unprecedented challenges in recent years, with Russia’s aggression against Ukraine, China’s military expansion in the East and South China Seas, and North Korea’s advancing nuclear and missile capabilities.

As stated in its defense white paper, Japan’s foremost priority is diplomatic efforts, emphasizing a commitment to peace and respect for international law. However, recognizing the need to protect its citizens and national interests, the country aims to enhance deterrence and make potential adversaries rethink attacking the nation.

Japan’s defense approach is guided by the National Security Strategy, National Defense Strategy, and Defense Buildup Program adopted in the previous year. These strategies focus on maximizing the effective use of existing equipment and strengthening future defense capabilities, including stand-off defense and unmanned assets.

At the core of its defense capability are the Self-Defense Forces (SDF) personnel. The white paper emphasizes efforts to improve their well-being, work environment, and treatment to ensure the smooth operation of advanced equipment.

Diplomatic efforts are gaining importance for defense, with Japan actively engaging in discussions and cooperation with allies like the United States and Australia. Joint development projects, such as the next-generation fighter aircraft with the United Kingdom and Italy, exemplify this collaboration.

Lastly, transparency and public understanding are crucial elements of Japan’s defense initiatives. The white paper serves as a critical tool to provide information on the security environment and the MOD/SDF activities to gain both national and international support.


In conclusion, as Japan unveils its plan to procure advanced ASEVs amidst rising regional threats and global uncertainty, the country demonstrates its commitment to fortifying its defense posture and ensuring peace and stability in the face of escalating security challenges posed by neighboring countries. Introducing these sophisticated vessels represents a crucial step in enhancing its missile defense capabilities, acting as a deterrent against potential threats and bolstering the country’s ability to protect its territorial integrity and national interests in a rapidly changing and increasingly complex geopolitical landscape.