If war breaks out in the Taiwan Strait, how the U.S. and Japan’s “spear and shield” strategy works

Japan sees the Chinese Communist Party as the main threat to the Self-Defense Force’s many advantages anti-submarine capabilities under the world

A Type 16 Mobile Combat Vehicle (16MCV) fires during a live fire exercise by the Japan Ground Self-Defense Force (JGSDF) at the East Fuji Maneuver Area on May 22, 2021 in Gotemba, Shizuoka Prefecture, Japan.

As tensions continue to rise in the Taiwan Strait, what role can Japan play in the event of U.S. military involvement in the Taiwan Strait? A report analyzes what support Japan could provide to U.S. forces in the event of a possible war in the Taiwan Strait, whether it could contribute to the war effort, and the legal and political issues associated with it, under the U.S.-Japan “spear and shield” strategy.

U.S. President Joe Biden and Japanese Prime Minister Yoshihide Suga emphasized “the importance of peace and stability in the Taiwan Strait” in their joint statement following the April 16 summit, the first time since 1969 that the U.S. and Japanese leaders have mentioned Taiwan in a statement. This has sparked much discussion about how the two allies would work together if peace in the Taiwan Strait is broken.

Jeffrey Hornung, a political scientist at Rand Corp, a U.S. think tank, said controlling the maritime choke point could be one of Japan’s most important contributions in a potential conflict with the Chinese Communist Party.

U.S.-Japan “Spear and Shield” Strategy

The U.S. Department of Defense hired Hornung to write a report entitled Japan’sPotentialContributions in an East China Sea Contingency.

The 160-page report points out that after the Cold War, the Japanese military shifted its defense focus from the Soviet Union to the Chinese Communist Party, especially the Ryukyu Islands, which are close to mainland China and Taiwan, where Japan’s three self-defense forces, air, land, and sea, have strengthened their forces. For example, the Land Self-Defense Force set up more missile batteries in the Ryukyu Islands and deployed electromagnetic equipment to jam Chinese communist communications. The Air Self-Defense Force, for its part, has a new Southwest Air Defense Force in the southwest, deploying an air defense missile regiment. The Maritime Self-Defense Force has strong anti-submarine and anti-ship capabilities to ambush CCP submarines that may attempt to break out of the first island chain and into the greater Pacific Ocean. In wartime, all three SDFs could help U.S. forces by blocking the “choke points” of Chinese communist forces to and from the Pacific Ocean.

The report begins by stating that the Chinese Communist Party is already considered a “major security threat” in Japan’s strategic arms thinking.

The report also analyzes the SDF’s broad advantages, including its high level of cooperation with the U.S. military, its alignment of equipment, tactics, terminology and training with the U.S. military, its strong Aegis and Patriot missile defense capabilities, and its development of new areas of operations such as space, cyber and electronic warfare.

In addition, the report analyzes how, in the event of a war in the Taiwan Strait, Japan could, under a newly revised law in 2015, help support U.S. forces with logistics, intelligence, blockade and other support in accordance with “the event of an armed attack against a foreign country with which Japan has close ties and which therefore threatens the survival of Japan” without its own country being attacked, or even The Self-Defense Forces can be deployed directly against Chinese communist ships.

Since the SDF’s inception in 1954, Japan has not sent any troops into combat. The strategy of shedding American blood and sweating Japanese troops has often been described as “shield and spear,” with the SDF’s responsibility as a shield to defend Japan and the U.S. forces stationed there, and the U.S. forces as a spear to strike outside Japan. Today, if a war does occur that threatens Japan’s survival, on a practical level Japan fears that it will both sweat and bleed.

This article introduces the armament of Japan’s Self-Defense Forces and its advantages, including the advantages of cooperation between Japanese and U.S. forces; the next article will introduce the circumstances under which Japan can participate in the war if war breaks out in the Taiwan Strait, and the related legal and political issues.

I. Japan’s Armament Strategy Thought of Communist China as a “Major Security Threat”

According to Article 9 of the Japanese Constitution, Japan will forever renounce war and the threat or use of force as a means of settling international disputes, and declares that it will not maintain a war capability. It is for this reason that the three branches of the Japanese military are not referred to by the terms Army, Navy and Air Force, but by the terms Ground Self-Defense Force (GSDF), Maritime Self-Defense Force (MSDF) and Air Self-Defense Force (ASDF).

The concept of “exclusive defense” is derived from Article 9, which means that all force is limited to the “minimum necessary level” for self-defense, so Japan does not possess intercontinental ballistic missiles ( ICBMs, intermediate-range ballistic missiles (IRBMs), long-range bombers, and aircraft carriers, which are considered to be beyond the “minimum necessary level” for self-defense.

According to Japan’s only National Security Strategy (NSS), released in 2013, North Korea is considered a major near-term threat, Russia is a declining power, a threat to Europe, not an imminent threat to the Asia-Pacific, and the Chinese Communist Party is a long-term, major security threat.

Japan’s concerns about the CCP include the CCP’s “continued increase in military spending without transparency and the rapid increase in military capabilities in a wide range of areas” as well as its “attempts to change the status quo through coercion based on its own claims. While most Japanese strategic planners believe that the CCP will not directly attack Japan, the CCP is considered a “major security threat.

According to the 2018 release of Japan’s National Defense Planning Guidance (NDPG) and Medium Term Defense Plan (MTDP), Japan has shifted from its traditional Cold War concerns about land invasion in the north of the Soviet Union to a focus on protecting Japan’s southwestern islands from CCP provocations. The Japanese government believes that Japan could lose a war with the CCP if its current level of SDF armament remains unchanged. As a result, all three of Japan’s Self-Defense Forces have made efforts to upgrade their equipment, develop new strategies, redeploy, become more mobile and coordinated, and more to meet the Chinese Communist challenge.

French Army Lieutenant Colonel Lenri Marcaillou (left), Japanese Self-Defense Force Colonel Masashi Hiraki (center) and U.S. Marine Corps Lieutenant Colonel Jeremy Nielson (right) pose after a news conference during a joint military exercise between the United States, Japan and France in Ezo, Miyazaki Prefecture, Japan, May 15, 2021. (right) pose for a photo after the press conference. (CHARLY TRIBALLEAU/POOL/AFP via Getty Images)

Land Self-Defense Force Increases Strength in Ryukyu Islands

The Land Self-Defense Force (GSDF) is the largest of Japan’s self-defense forces. Before the collapse of the Soviet Union, the focus was on preventing Soviet land invasion in northern Japan, so heavy armored divisions equipped with tanks and long-range artillery were deployed in Hokkaido, and after the collapse of the Soviet Union, the GSDF lost its direction for a while and began to focus on peacekeeping, rescue and other operations outside of war.

The Land Self-Defense Force has 138,126 personnel and is divided into five military districts, comprising a total of eight infantry divisions, one armored division, six infantry brigades, and a number of other artillery, air defense artillery, and engineering units. The largest military district was the Sapporo-based Northern Army, consisting of two divisions and two brigades.

With the increase in Chinese Communist provocations in the East China Sea, the Land Self-Defense Force has been reoriented to respond primarily to incidents in southwestern Japan.

Previously, with only the 15th Brigade and a small garrison on Tsushima Island in northern Kyushu, the Land Self-Defense Force has increased its troop deployment throughout the Ryukyu Islands: a Coastal Observation Unit (COU) and logistics facility was established in 2016 on Yonaguni Island (Yonaguni) with approximately 160 personnel to gather intelligence and conduct continuous In March 2019, two additional bases were established in Amamioshima and Miyakojima, deploying surface-to-air missiles (SAMs) and anti-ship cruise missiles (ASCMs).

The Land Self-Defense Force (LDF) is also actively strengthening its ability to collect and manage electromagnetic intelligence from enemy ships and aircraft, and enhancing electromagnetic jamming equipment to interrupt enemy radar and communications. This includes the development and production of high-powered jamming equipment to interfere with enemy unmanned aerial vehicles (UAVs) and early warning aircraft (AEW&C), enabling close range electronic warfare within 5 kilometers. The Land Self-Defense Force is also developing a road-mobile Network Electronic Warfare System (NEWS) to analyze electronic waves and conduct electronic warfare. Designed for island defense, the system consists of several specially equipped electronic warfare vehicles that conduct electronic reconnaissance while crippling an adversary’s command, control, and communications networks.

To improve its off-island combat capabilities in the Ryukyu Islands, the Land Self-Defense Force began reducing some of its less transportable equipment, such as tanks and heavy artillery, and shifting to more mobile equipment.

The Japan Ground Self-Defense Force (JGSDF) conducts a live-fire exercise in the East Fuji Maneuver Area, Gotemba City, Shizuoka Prefecture, Japan, May 22, 2021. Pictured is a UH-1J helicopter. (AKIO KON/POOL/AFP via Getty Images)

Air Self-Defense Force establishes new Southwest Air Defense Force

The Air Self-Defense Force (ASDF) is the second largest branch of the SDF, with the advantage of advanced fighters and skilled pilots. Throughout the Cold War, it mainly dealt with former Soviet aircraft. However, over the past 20 years, the focus has shifted to dealing with the growing air challenge of the Chinese Communist Party in the East China Sea. To that end, Japan plans to purchase a total of 105 F-35As and 42 F-35Bs to replace its retired fleet of F-4EJs.

The Air Self-Defense Force has 42,785 personnel and consists of 416 fixed-wing aircraft (349 of which are fighters) and 15 transport helicopters. It is divided into three air defense zones: northern, central and western. Each defense area consists of two fighter wings, an aircraft control and warning wing, and one or two missile regiments.

In response to increasing Chinese Communist activity, in 2017 the Southwest was elevated to a Southwest Defense Zone on par with the other three defense zones, with its own sector air defense force called the Southwest Air Defense Force. Today the SWADF consists of a fighter wing (9th Wing) consisting of two F-15 fighter squadrons, an aircraft control and warning wing, and a missile regiment.

Due to the limited airfields and facilities in the Ryukyu Islands, the Japanese government decided to procure F-35Bs with vertical takeoff and landing capability and convert its two Izumo-class helicopter destroyers into multirole destroyers capable of functioning as fixed-wing aircraft carriers. The aircraft carrier type capability improves the flexibility of fighter operations.

Fourth, the Maritime Self-Defense Force anti-submarine capabilities of the world’s best

In terms of numbers, the Maritime Self-Defense Force (MSDF) is the smallest, but the MSDF is the most distinctive, and its biggest single advantage is that its anti-submarine capabilities are considered “the best in the world” and can “choke” on sea lines of communication in wartime. During the Cold War, one of the SDF’s main missions was to monitor Soviet submarines and protect U.S. ships. These submarines operated in the deep waters of the Pacific Ocean and in the waterways around Japan.

The Maritime Self-Defense Force has 42,289 personnel and, as of 2018, has 135 surface and submarine ships, 47 of which are destroyers. The Maritime Self-Defense Force also has 163 aircraft, including 73 P-1 and P-3C patrol aircraft and 90 rotary-wing aircraft.

Because of the maritime challenge posed by the Chinese Communist Party in the Ryukyu Islands region, the Japanese government has spent significant resources to strengthen the Maritime Self-Defense Force’s key capabilities.

Central to this is equipping the Maritime Self-Defense Force with more advanced destroyers and submarines to enable it to conduct anti-submarine and intelligence, surveillance and reconnaissance (ISR) operations, including equipping Aegis destroyers, a key pillar of Japan’s ballistic missile defense (BMD) system. The Maritime Self-Defense Force aims to achieve a fleet of 54 destroyers and 22 submarines by about 2024. Importantly, over the next decade, Japan will take steps to enable vertical takeoff and landing F-35B aircraft, capable of operating from ships, to further increase the flexibility of fighter operations.

The Maritime Self-Defense Force’s surface and submarine fleets are fully capable of defending sea lines of communication (SLOCs) and providing a “chokehold” on sea lines of communication in the region. For example, the Maritime Self-Defense Force has strong anti-submarine and anti-ship capabilities to ambush Chinese Communist submarines that may attempt to break out of the First Island Chain and into the greater Pacific Ocean.

Since the U.S. Navy’s Seventh Fleet has few anti-mine ships, the Maritime Self-Defense Force also has a superior minesweeping fleet to provide strong support to U.S. forces.

The Japan Ground Self-Defense Force (JGSDF) conducts a live-fire exercise in the East Fuji Maneuver Area, Gotemba City, Shizuoka Prefecture, Japan, May 22, 2021. (AKIO KON/POOL/AFP via Getty Images)

V. The many advantages of the Self-Defense Forces

Despite the absence of the name “army,” the SDF is a modern army with highly trained personnel. The SDF has three major strengths: 1. high level of cooperation with the U.S. military, 2. strong air and missile defense capabilities, and 3. priority for new areas such as space, cyber, and electronic warfare.

  1. High level of cooperation with the U.S. military

Similar equipment: U.S. and Japanese militaries are similarly equipped, and Japan procures more than 90 percent of its weapons from the United States, including F-35 fighter jets, Aegis combat systems, E-2D airborne early warning aircraft, KC-46 refueling aircraft, Global Hawk unmanned aircraft systems and Osprey V-22 tilt-rotor aircraft, as well as various missiles such as SM-3 missiles and Block IIA interceptor missiles, among others. Similar equipment minimizes the technical difficulties of cooperation between the two sides and allows for mutual support in logistics. For example, in March 2017, the U.S. Navy and the Maritime Self-Defense Force conducted an exercise to enable ship-to-ship exchange of repair parts.

Regular Training and Military Exercises: The U.S. and Japan have also had decades of mutual exercises and training covering all three branches of the SDF and all four branches of the U.S. military. This includes command and field training between the U.S. Army/Marine Corps and the Land Self-Defense Force, anti-submarine training and minesweeping training between the U.S. Navy and the Maritime Self-Defense Force, and air defense and fighter combat training between the U.S. Air Force and the Air Self-Defense Force, thus enabling each side to better support the other during contingencies.

Similar operational concepts and doctrine: Many military concepts and doctrines are shared between the two countries, using common language and terminology. For example, the Land Self-Defense Force is trained by the U.S. Army based on U.S. doctrine, exercises, and instructional methods; the Air Self-Defense Force is equipped and trained by the U.S. Air Force; and the Maritime Self-Defense Force’s role and mission is “based not only on Japan’s security and defense strategy, but also on the U.S. Naval Strategy and the U.S. National Security Strategy on which the Naval Strategy is based.” .

Providing maintenance support: Maintenance facilities operated by Japanese companies can also provide maintenance support for U.S. equipment; for example, Nippi, the only U.S. military aircraft maintenance company in Japan, has provided maintenance services for all U.S. Navy and Marine Corps aircraft since 1953, avoiding the delays associated with returning to the United States for repairs or upgrades to equipment.

  1. Strong air and missile defense system

Japan’s 2009 Defense of Japan White Paper acknowledged that “if Japan were to come under armed attack, such an attack … would most likely be a surprise air attack by aircraft or missiles.” To defend against these attacks, Japan has invested significant resources in its air and missile defense systems.

(1) Anti-missile capabilities: In the wake of the North Korean missile threat in the late 1990s, Japan began efforts to develop a national ballistic missile defense (BMD) system in two levels.

The first level is maritime interdiction, consisting of seven (soon to be eight) Maritime Self-Defense Force (MSDF) Aegis destroyers equipped with Standard 3 (SM-3) interceptor missiles, which can intercept incoming missiles in their midcourse phase. The destroyer fleet currently consists of four Vajra-class and two Atago-class destroyers, with the new Maya-class destroyers using the more advanced SM-3 Block IIA interceptor. By 2022, the two Atago-class destroyers will have completed their upgrades.

The second dimension is ground interdiction, done by the Air Self-Defense Force, using mobile Patriot-3 missile (PAC-3) defense systems, mostly deployed around metropolitan areas such as Tokyo. If Aegis misses an incoming missile, it is dealt with by the Patriot-3 missile system, which has an engagement range of only 12 miles. The Air Self-Defense Force currently has six missile regiments, each equipped with four Patriot-2 or Patriot-3 missiles, and in fiscal year 2020, Japan will equip 12 of these fire units with new Patriot-3 missiles. Patriot-3 missile enhancements.

Both ballistic missile defense systems are linked and coordinated through the Japan Air Defense Ground System (JADGE) network. “JADGE is also linked to U.S. communications satellites, allowing the United States and Japan to share air threat data against Japan (and U.S. bases).

In addition, the U.S. Seventh Fleet, based in Japan, has ships equipped with Aegis BMD systems that can relay or receive data with other Aegis ships, including Japanese destroyers, and land-based systems such as the Patriot-3 missile system, including Japanese and U.S. forces deployed in Okinawa.

Japanese Self-Defense Forces soldiers participate in a joint military exercise between the U.S., Japan and France in Ezo, Miyazaki Prefecture, Japan, May 15, 2021. (CHARLY TRIBALLEAU/POOL/AFP via Getty Images)

(2) Air defense capabilities: The Air Self-Defense Force and Maritime Self-Defense Force, both of which have their own air defense systems, use short-range anti-aircraft missiles for the Air Self-Defense Force and smaller Stinger missiles for the Maritime Self-Defense Force’s shore-based units.

As part of its expanding footprint in the Ryukyu Islands, the Land Self-Defense Force has been deploying Type 03 air defense missiles to the region and plans to upgrade these systems. The upgraded Type 03 systems have a maximum range of 100 kilometers compared to the Type 03’s 50-kilometer range and maximum engagement altitude of 10,000 meters.

Of all seven Air Defense Artillery Regiments (AA) in the Land Self-Defense Force, only one, the 15th Air Defense Regiment (AA) in the Ryukyu Islands, Okinawa, is equipped with three Type 03 air defense gun groups and one Type 11 air defense gun group.

In recent years, the Land Self-Defense Force has transferred air defense batteries from other locations, to bases on the Ryukyu Islands. in 2019, a Type 03 battery was transferred from the 3rd Air Defense Regiment in Fukuoka Prefecture to Amamioshima; in 2020, a similar battery was transferred from the 7th Air Defense Regiment in Nagasaki Prefecture to Miyako Island. In the coming years, a third battery is expected in the area, with the most likely destination being Ishigaki.

With air attacks also likely to come from the sea, the Land Self-Defense Force has begun deploying advanced batteries of Type 12 anti-ship cruise missiles (ASCMs) throughout the Ryukyu Islands, which have a maximum range of 200 kilometers and can be used against enemy ships approaching Japanese territory farther from shore. The SDF plans to disperse a number of batteries equipped with Type 12 missiles throughout the Ryukyu Islands.

The air defense missiles and anti-ship cruise missiles deployed by the Land Self-Defense Forces in the Ryukyu Islands form an air defense network that enhances Japan’s anti-access/area denial (A2/AD) capabilities and deflects additional risk to CCP military operations by denying CCP ships and aircraft freedom of maneuver in the East China Sea.

Assuming that CCP naval forces must pass through the Miyako Strait to threaten U.S. forces assembled in that area of operations, Japan’s anti-ship cruise missile capability makes it a “gatekeeper” in the area. This could allow Japan to “close off” the exit for Chinese communist forces trying to break through the first island chain, while also helping to create a safer passage for U.S. reinforcements entering the area.

(3) Development of new missiles: Japan is seeking to acquire longer-range missiles, with plans to include medium-range anti-ship missiles (JSM), air-to-ground precision missiles (JASSM) and long-range precision-guided anti-ship missiles (LRASM). The JASSM-ER has a range of about 900 km compared to the JSM’s maximum range of about 500 km.

Japan is also developing an improved supersonic air-to-ship missile (ASM), called the ASM-3, with a range of more than 400 km. the ASM-3 has a flight speed of about Mach 3 and will be installed on the successor to the F-2 fighter.

The SDF is developing a number of new missiles, one of which is the land-based Very High Speed Glide Gun (HVGP) with a maximum range of 300 kilometers. Over the next decade, the Ichikami Self-Defense Force will establish two HVGP battalions for the defense of remote islands. Likewise, development of new anti-ship cruise missiles is underway. These missiles could extend Japan’s military reach beyond Japan’s shores and increase the ability to strike at Chinese Communist military facilities.

  1. develop space, cyber, and electronic warfare capabilities

In the 2018 National Defense Program Guidelines, Japan intends to develop three “new” areas: cyber, space, and electronic warfare.

Space: For much of the past decade, Japan has been working to develop capabilities that include a modern space situational awareness (SSA) system, which consists of low Earth orbit radars, telescopes, and deep space radars and operational systems.

Japan’s Ministry of Defense is currently developing three major measures. One is the development and enhancement of Japan’s Space Situational Awareness (SSA), and in May 2020, the Ministry of Defense launched a new 20-person space operations unit within the Air Self-Defense Force designed to track threats to Japanese surveillance satellites, such as space debris and satellites operated by other nations.

The second is the development of the Quasi-Zenith Satellite System (QZSS) as an alternative to the U.S.-operated Global Positioning System (GPS) to enable the SDF and other users to obtain positioning, navigation, and timing (PNT) information in and around Japan without relying on GPS.

The third is the development of an X-band defense communications satellite network that is intended to help streamline the SDF’s communications systems and ensure stable communications links. This is particularly important as the SDF moves to the Ryukyu Islands, which have a large body of water.

Cyber: To date, the SDF’s focus on cyber has been primarily defensive, but is now seeking capabilities to disrupt adversary networks.

Electronic Warfare: Electronic warfare (EW) consists of three elements: electronic attack (EA), electronic protection (EP), and electronic warfare support (ES). The SDF has largely focused its efforts on electronic warfare support, with electronic attack capabilities limited to self-defense and training, and insufficient disruption capabilities in actual warfare.

The SDF is now determined to develop the capability to disrupt enemy operations by jamming electromagnetic energy. For example, the FY 2019 defense budget establishes the Electromagnetic Spectrum Policy Office in the Ministry of Defense and the Electromagnetic Spectrum Field Planning Section in the Joint Staff. In addition to procuring the F-35A, which has advanced electronic warfare capabilities, and the F-35B, the Ministry of Defense is improving the electronic warfare capabilities of the F-15.

The Ministry of Defense wants to develop aircraft and vehicles that can disrupt enemy radar and radio signals, and the Land Self-Defense Force is also developing a road-mobile Network Electronic Warfare System (NEWS) to analyze electronic waves and conduct electronic attacks. Designed for island warfare, the system consists of several specially equipped electronic warfare vehicles designed to conduct electronic reconnaissance while crippling an adversary’s command, control and communications networks.

The Ministry of Defense also hopes to develop systems to jam enemy aircraft radars and to develop ground jammers to strike foreign satellites or airborne early warning aircraft from the ground.