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  • JTMS Intern Tyler Nguyen

Improving Amphibious Capabilities: Japan’s New Expeditionary Force

DDH-183 Izumo
Japan Naval Ship DDH-183 Izumo at Yokosuka Naval Port

I. Introduction

After Japan’s defeat in World War II, its surrender agreement prevented the country from having certain military capabilities. Article 9 of the 1947 constitution states,

“In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as

well as another war potential, will never be maintained. The right of belligerency of the

state will not be recognized."

Today, Japan's armed forces are considered a Self Defense Force as per its policy of non-involvement. However, Section 2 of Article 3 that was signed on January 9, 2007, altered the role of the JSDF, and in 2020 we can see that their military capabilities are not much different from militaries of other regional powers – see figure 1. As of the 21st century, logistics technologies have evolved, but trading and shipping through means of sea/water transportation is still more popular than air travel due to the lower cost and greater load capacity compared to aircraft. The sea has also become an essential resource for militaries seeking to transport large numbers of troops, equipment, and supplies in times of conflict and war. This leads to water-locked countries like Japan, U.K., and Australia emphasizing having a powerful navy. Although the United States is not water-locked, it still holds the world's largest navy as a means to assert its dominance, as it must access many of its foreign interests through the Pacific and Atlantic Oceans. In 2013, the JMSDF (Japanese Maritime Self Defense Force) launched the Izumo class, a “helicopter-carrying destroyer” that is comparable to the U.S. Navy’s Wasp or America-class LHD (Landing Helicopter Dock).[i] Although these ships, being unable to launch aircraft through an aircraft catapult system, are not considered aircraft carriers, their roles have changed with the introduction of Vertical Takeoff and Landing (VTOL) fighters such as the F35 produced by Lockheed Martin. As of 2020, Japan has confirmed that the Izumo class will be refitted to operate with F-35B fighters and has ordered F-35 and F-35Bs from the U.S. Seeing that Japan now has a naval force that has the capability to operate similarly to a U.S. Expeditionary Unit (MEU), does this plan present a threat to its N.E. Asian neighbors by giving Japan an expeditionary force capability?

Military Firepower Index
Figure 1[ii]

II. Japanese Carrier Capabilities and Intent

As of 2020, the Japanese government still maintains its stance that their military is only used for defensive purposes, hence the name Japanese Self Defense-Force. By definition, the Japanese Maritime Self-Defense Force can not and does not have an aircraft carrier as, traditionally, this is a class of ship used for offensive capabilities, namely power projection. However, the Japanese government has been able to maneuver around this technicality by obtaining ships with the classification of a helicopter-carrying destroyer and turning it into a modern-day "aircraft carrier" in all but name. According to the Royal Institution of Naval Architects, in October of 2016, the Izumo- class ships, designated as helicopter-carrying destroyers, were not yet capable of operating fixed-wing aircraft.[iii] As the JSDF, at the time, had not obtained or were not planning to purchase VTOL fighters like the F-35B from the U.S., the idea of the Izumo-class having the same capabilities as the U.S. Navy’s LHDs or LHAs was only seen as a hypothetical. Fast forward to 2020, and the Japanese government confirmed in its 2020 Defense White Paper (Japan's annual defense report) that the Izumo-class ships, the Izumo and Kaya, were to be refitted to operate the F-35B.[iv] In 2020, the U.S. State Department approved the sale of 42 F-35Bs and 63 F-35As to Japan, who’s intent was to operate the newly purchased F-35Bs from the Izumo-class ships.[v] Now with the capability to deploy VTOL aircraft from their ships, Japan has similar capabilities to that of the U.S. military’s expeditionary forces.

Now that Japan, a water-locked nation, has the ability to deploy a maritime expeditionary force, should their Northeast Asian neighbors feel threatened? As Japan has elected a new prime minister, Yoshihide Suga, it is not possible to tell for certain what his plans are concerning international diplomacy. As Prime Minister Suga was Abe's chief cabinet secretary, many believe that his policies will not be different, a sentiment that Suga echoed publicly.[vi] Given Suga holds the same line with Abe's history of international diplomacy, it would be safe to say that China, North Korea, and, at least theoretically, South Korea would be the Northeast Asian countries most threatened by Japan's new military capabilities. Given Japan’s historically pro-US stance and its tensions, especially in the Senkaku/Diaoyu Islands, it is likely that Japan will continue to see China as a hostile neighbor.[vii] Referring back to Japan’s 2020 Defense White Paper, the report states,

“China has thus relentlessly continued attempts to unilaterally change the status quo by

coercion in the sea area around the Senkaku Islands, leading to a grave matter of

concern. Japan cannot accept China’s actions to escalate the situation.”

Given North and South Koreas’ history of animosity towards Japan, dating back to Japan's colonization of the Korean peninsula, and North Korea's constant threats to Japan’s security, it is likely that North Korea also sees Japan’s new expeditionary capabilities as a threat given their proximity. Also, since the U.S. and South Korea are still technically at war with North Korea, the JSDF is highly likely to aid the two countries against North Korea in the event of armed conflict.

III. What is an ‘expeditionary force’?

Now that there is an acknowledgment of Japan’s new maritime capabilities and its perceived threat, it is important to know what an expeditionary force is and why its ability to project power gives Japan’s defense force a greater edge on the battlefield. An expeditionary force has traditionally been used for amphibious coastal landing operations, being able to carry troops, aircraft, transport vehicles, and supplies for missions across the ocean. The United States Marine Corps, the U.S. military’s primary amphibious operations branch, has been the de facto model that militaries worldwide have trained with and aspired to. With its joint operations with the U.S. Navy, the U.S. Marine Corps can deploy anywhere in the world via air, land, or sea due largely to the U.S. Navy's capabilities of force projection. The basic idea of force or power projection is being able to project military presence to serve national interests. In short, expeditionary forces are able to do this because they can command and dominate through air, land, and sea. The reason that expeditionary forces are able to establish this unified dominance is that they are comprised of different ships to fit every operational need and can be flexible to meet various missions. The U.S. military’s MEUs (Marine Expeditionary Units) are typically deployed under an Expeditionary Strike Group (ESG) or Amphibious Ready Group (ARG).[viii] ESGs are typically comprised of three amphibious carriers, guided-missile destroyers (DDG),[ix] a guided-missile cruiser (C.G.),[x] and a submarine. ARGs typically have an amphibious carrier, a landing platform dock (LPD),[xi] and a dock landing ship (LSD).[xii] With the MEU as the lead ship aboard a Landing Helicopter Assault (LHA) or Landing Helicopter Dock (LHD),[xiii] the ships around them are there to support, and if need be, protect the lead ship while conducting amphibious operations.

IV. Japanese Plans

Japan plans to deploy its F-35B jets on the Izumo and Kaga starting in 2024, and they have already begun refitting the two Izumo-class ships to operate VTOL aircraft.[xiv] Japan also seeks to use the U.S. military's V-22 Osprey, a tiltrotor aircraft primarily used by the U.S. Marine Corps, and was delivered its first Osprey in July 2020.[xv] Given that Japan is the first country outside of the U.S. to use the V-22 Osprey, it is clear that Japan seeks to further upgrade its amphibious capabilities as the aircraft has been used heavily in U.S. MEU operations. However, according to retired U.S. Navy Rear Admiral McDevitt at the U.S. Naval Institute, China will have the world's largest Navy in 2035 and, as of 2020, has already surpassed the Japanese Navy.[xvi] Although Japan has now lost its spot as the dominant naval power in Asia in terms of the number of ships compared to China, Japan's ships are still technologically superior to China's and still have the backing of the U.S. military. It is also unlikely to see the U.S. and Japan sit idly by as China's naval capabilities grow. So, does this plan present a threat to its NE Asian neighbors by giving Japan an expeditionary force capability? Looking at Japan's current fleet of ships, they will have the capability to operate similar missions to an ESG. With the Japanese Navy's three amphibious transport docks, 37 destroyers (8 DDGs and 29 D.D.'s), 19 submarines, an amphibious fighting force (Japan’s Amphibious Rapid Deployment Brigade), an expeditionary airpower that is being modeled after the U.S.'s,[xvii]and their future VTOL capable ships, the Japanese Navy will soon be able to deploy its own ESG missions.

V. Conclusion

With that knowledge, yes, now that Japan has growing amphibious capabilities, it has the ability to deploy its ground forces through sea transportation in the event of a future conflict against China, North Korea, or any other enemy that threatens its defense. However, although we will see an upgrade in military projection potential once Japan can deploy an ESG, it is still unlikely that these upgrades alone would be sufficient for China to consider them a threat to Chinese coastal security. China, given its superior number of both ships and ground troops and its hypersonic anti-ship missiles that were developed for destroying U.S. carrier fleets, has sufficient defensive capabilities to rebuff any potential landing force. On another point, given that Japan’s military is, at least in name, meant for defense and the only foreseeable conflicts would be against China and North Korea, is an amphibious force necessary given its proximity to the two countries and its alliance with the U.S.? As Japan's military was created as a defense force but has recently seen upgrades in offensive capabilities, these upgrades would seem to violate the Peace Constitution and change the posture of the so-called "Japanese Self Defense Forces." This violation and the growth of Japanese military capabilities may also cause a naval arms race in the region, as a Japanese naval build-up may spark renewed feelings of threat from countries who experienced the Empire of Japan's colonial ambitions during WW2. This would only exacerbate the already tense situation in the region. However, Japan could potentially ease such tensions with countries of interest through joint exercises, measures of transparency, and military personnel exchange programs, which military rivals have long used as methods to both relieve tensions and create trust. The US has not made any public comments condemning or approving the Japanese naval build-up, but given the current state of US/Japan bilateral relations and the continued approval of the sale of military equipment/weapons to Japan, it would be hard to argue that the U.S. does not support the recent moves by Japan’s military. The U.S. military would most likely support Japan's actions as it allows U.S. forces stationed in Japan to leverage the developing Japanese amphibious capabilities in future conflicts. It is also unlikely that neighboring South Korea would see Japan’s new amphibious capabilities as threatening due to their third-party relation through the U.S. Also noteworthy is that South Korea has its own amphibious capabilities with its Dokdo-class amphibious assault ships and is in the works of creating its own aircraft carrier.[xviii]


[i] Izumo Class Far from Carriers in the Fullest Sense.” RINA News RSS, Royal Institution of Naval Architects, Oct. 2016, Accessed December 1, 2020.

[ii] Armstrong, Martin. “Infographic: The World's Most Powerful Militaries.” Statista Infographics, 8 Jan. 2020, Accessed December 12, 2020. [iii]Ibd. [iv] Allison, George. “Japan Confirms That 'Helicopter Destroyer' Izumo Will Operate F-35B Jets.” U.K. Defence Journal, July 14, 2020, Accessed December 1, 2020. [v] Allison, George. "U.S. Approves Sale of 105 F-35 Jets to Japan, Including F-35Bs for Carrier." U.K. Defence Journal, July 10, 2020, Accessed December 1, 2020. [vi] Crabtree, Charles, and KiyoteruTsutsui. “Five Ways in Which Japan's New Prime Minister Suga Is Different from Abe.” TheHill, September 20, 2020, Accessed December 1, 2020. [vii] Mochizuki, Mike, and Jiaxiu Han. "Is China Escalating Tensions With Japan in the East China Sea?" The Diplomat, September 16, 2020, Accessed December 1, 2020. [viii] “Amphibious Ready Group And Marine Expeditionary Unit Overview.” Marines, Accessed December 12, 2020. [ix] “Destroyers (DDG 51).” America's Navy, November 13, 2020, Accessed December 12, 2020. [x] "SURFPAC's Ticonderoga Class Cruiser (C.G.) Info Page." America's Navy, Accessed December 12, 2020. [xi] “SURFPAC's Amphibious Transport Dock (LPD/LPD17) Info Page.” America's Navy, Accessed December 12, 2020. [xii] “Dock Landing Ship - LSD.” America's Navy, July 19, 2019, Accessed December 12, 2020. [xiii] “Amphibious Assault Ship (LHD/LHA) Info Page.” America's Navy, Accessed December 12, 2020. [xiv] Takahashi, Kosuke. "Japan Begins Refitting First of Two Izumo-Class Carriers to Support F-35B Operations." Janes, June 30, 2020, Accessed December 1, 2020. [xv] Eckstein, Megan. "Japan Self-Defense Force Accepts Delivery of First V-22 Osprey." USNI News, July 14, 2020, Accessed December 1, 2020. [xvi] McDevitt, Michael A. “China's Navy Will Be the World's Largest in 2035.” U.S. Naval Institute, April 1, 2020, Accessed December 1, 2020. [xvii] SETH ROBSON, SETH. "Japan Is Building an Expeditionary Air Force, with Help from the U.S. Military." Stars and Stripes, September 15, 2020, Accessed December 12, 2020. [xviii] Lendon, Brad, and Yoonjung Seo. “As Tensions Rise in Asia Pacific, South Korea Is Building Its First Aircraft Carrier ... Complete with US-Made Fighter Jets.” CNN, August 12, 2020, Accessed December 12, 2020.

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