With China’s growing presence in mind, the United States is reorganizing its forces into smaller, distributed units while bolstering information sharing with Japan and South Korea for a more integrated response to possible contingencies.

At the U.S.-South Korea summit on April 26, Washington and Seoul agreed to enhance their extended deterrence under the U.S. nuclear umbrella.

Japan, however, still faces a pile of challenges over the command flow and operations of the Self-Defense Forces despite the rising probability of a Taiwan crisis transpiring.

Ryoichi Oriki, former chief of staff of the SDF’s Joint Staff, expressed a sense of urgency.

“The military balance in the Western Pacific is on the verge of collapse,” he said. “One estimate predicts China’s military power will surpass that of the United States in 2025.”

Beijing’s anti-U.S. security policy is known as Anti Access/Area Denial (A2/AD).

Under the framework, China is expected to take measures to prevent U.S. troops from entering the First Island Chain in the South China Sea extending from Kyushu through Taiwan’s east side.

China is also said to be taking steps to prevent free movement of U.S. units in the Second Island Chain linking Japan’s Izu and Ogasawara islands with Guam, Saipan, Palau and the Marianas.

UNIT REORGANIZATION

In response, Washington is forging ahead with new tactics for its forces.

The U.S. Navy and Air Force have traditionally been deployed on the assumption that they can take control of the seas and skies.

But under a new scenario being discussed, U.S. troops fail to overwhelm their Chinese counterparts in the skies and waters near the First Island Chain.

U.S. units are separated into two categories: Inside Units sent to zones exposed to threats from the seas and skies, and Outside Units stationed in relatively safe areas.

Mark Gunzinger, a former U.S. deputy assistant secretary of defense, touched upon the planned U.S. response to an emergency in Taiwan.

“There’s a potential ... you’ll have a major fight with China that could involve Japan,” Gunzinger said.

He said that a few years ago, following a range of discussions, U.S. forces decided to fight along with their allies in risky “Inside” areas.

Under the renewed course of action, the U.S. Navy, Air Force, Army and Marine Corps are reorganizing their units.

The Japan-U.S. Security Consultative Committee announced in January this year that the U.S. 12th Marine Regiment in Okinawa Prefecture will be turned into the 12th Marine Littoral Regiment (MLR) by 2025.

The envisioned regiment will be responsible for the Expeditionary Advanced Base Operations (EABO), with the aim of deploying units following detection of a sign of an enemy attack.

The MLR will be armed with missiles, air defense features, logistics abilities and other functions, allowing itself to launch attacks while mobile.

It will also collect enemy intelligence to provide a strategic foothold for reinforcements.

The MLR is considered a mainstay among Inside Units.

In the run-up to the MLR’s introduction, the U.S. Marine Corps conducted joint training with the Ground SDF’s land-to-ship missile regiment.

“The MLR will likely work around the southwestern Nansei Islands, Taiwan, the Philippines and elsewhere on the First Island Chain,” said Katsuki Takata, a former commander in chief of the SDF’s Ground Component Command.

The U.S. Army in 2017 started putting in place its Multi-Domain Task Force (MDTF), which is in charge of cyberspace and other fields.

Gen. Vincent Brooks, a former commander of the U.S. Army Pacific and U.S. Forces Korea, described the MDTF as a unique organization fitted with functions suited for modern warfare.

The U.S. Army set up an airborne division in Alaska in June 2022.

“That allows additional commanding control to conduct independent combat operations, introduced by parachute, anywhere from the Arctic Circle, to the Himalayas, to the jungles of Thailand, or Cambodia, down into Indonesia, I mean, anywhere in the region,” Brooks said.

The U.S. Navy is moving ahead with its Distributed Maritime Operations (DMO) in the hope of making available a horde of small unmanned vessels.

“DMO is really turned into how the U.S. Navy will fight the Chinese navy, in the Western Pacific, mostly around Taiwan,” stated Bryan Clark, a senior fellow at the U.S. Hudson Institute. “And they’re focused on how to have a survivable naval force, because it’s distributed its people to missile fires against Chinese navy ships that might be threatening Taiwan.”

The U.S. Air Force is carrying out drills to supply sets of fighters, fuel, ammunition and other materials to airports that were formerly not used as its bases under the Agile Combat Employment (ACE) concept.

An F-35A fighter jet from Alaska was stationed on the island nation of Palau in the Pacific in June 2022. Redevelopment work of an airfield on Peleliu in Palau has gotten under way as well.

Against the backdrop of changes in the U.S. armed forces, the U.S. Department of Defense is putting more emphasis on their network with the help of the Joint All-Domain Command and Control (JADC2).

“The benefit to that is it hardens all of our forces against attacks, which are not just physical attacks by missiles and bombs and so forth, but also cyber strikes, electronic warfare attacks, and so forth,” Gunzinger said. “That means that we've solved all the problems with interoperability.”

COORDINATION WITH ALLIES

Washington sees bolstered ties with Tokyo and Seoul as indispensable for containing China. And the United States has been stressing the significance of security cooperation among the three nations.

The April 26 U.S.-South Korea summit in Washington marked the 70th anniversary of their bilateral alliance. Plans to ramp up trilateral ties were also reaffirmed there.

Japanese Prime Minister Fumio Kishida visited South Korea on May 7 and discussed bilateral issues, including security.

Washington expects Seoul to prevent North Korea from taking military action simultaneously with a Chinese invasion of Taiwan.

“The reality is that no important security or economic issue in the region can be addressed without both South Korea’s and Japan’s active involvement,” said Harry Harris, a former U.S. ambassador to South Korea who once led the U.S. Indo-Pacific Command.

Brooks explained why the United States is shoring up relations with its allies.

“Their effort is to continue to cause doubt in the minds of the People’s Liberation Army and the Chinese Communist Party leadership that they can have success. There should be doubt in their minds about whether they (China) can do this,” he said. “And that delays the onset of when a crisis would occur.”

Brooks noted the SDF and the South Korean military need to be connected with the JADC2 system for that objective.

An era is believed to be nearing when Washington, Tokyo and Seoul should work closely together in mutual information sharing for not only ballistic missile defense but also various other operations.

Reorganized U.S. forces have jointly trained with the SDF for a potential Taiwan crisis.

According to several inside sources, Washington apparently wants the SDF to defend U.S. bases in Japan and other Japanese territories.

Such expectations include the SDF supplying fuel and ammunition to U.S. units operating around the Taiwan Strait.

If U.S. forces are exposed to enemy attacks, Tokyo is expected to declare that Japan’s survival is being threatened and the country can, therefore, exercise its right to collective self-defense in line with national security legislation introduced in 2015.

Russia’s invasion of Ukraine has fueled a sense of alarm among Japanese politicians and SDF officials.

Japan’s National Security Strategy, approved by the Cabinet in December last year, calls for deepening security cooperation with the United States. The description may make China feel cautious about fighting the United States because it could lead to direct conflict with Japan.

Amid the enhanced U.S.-Japan security ties for a possible clash with China, Tokyo is required to make every diplomatic effort to prevent Beijing from receiving the wrong message about Japan’s heightened defense ability.

HURDLES FOR SDF

Marking a drastic shift from its postwar defense approach, Japan recently approved three key revised security policy documents, including the National Security Strategy.

Japan now has a “counterstrike” capability to attack enemy bases.

“The measure aims to supplement the collapsing military balance in the West Pacific and deter conflict,” said Oriki, who once served as the SDF’s highest-ranking officer.

However, the SDF still faces hurdles in changing its existing system to adapt to the new environment.

The SDF is proceeding with a southwestern shift as part of a countermeasure against China.

An SDF camp opened in March this year on Ishigakijima island in Okinawa Prefecture following those on nearby Yonagunijima, Amami-Oshima and Miyakojima islands.

Although the new camp would be regarded as the forefront line of Japan’s defense during a Taiwan invasion, detailed arrangements for bilateral cooperation have yet to be made with U.S. forces.

The separation of roles between the SDF and the U.S. Marine Corps’ MLR has not been determined, although the MLR would be deployed earlier than other units in an emergency.

The SDF also apparently lags behind the U.S. side concerning a comprehensive reorganization of naval, air and land forces.

Another problem is determining who will issue commands at all levels during emergencies.

The National Security Strategy refers to the decision to install a permanent joint command to unify SDF control.

But Goro Matsumura, a retired chief of the GSDF’s northeastern regional headquarters, pointed to a political void.

“No mechanisms have been worked out to specify how far politicians will leave decisions up to the joint commander and units in battlefields,” Matsumura said.

Japanese law also does not make clear each commander’s authority and responsibility.

Linking the SDF with the JADC2 may result in the U.S. side taking effective control of all troops, given the nation’s overwhelming amount of intelligence at hand.

Defense coordination guidelines should be developed beforehand to bypass the issue, but no concrete moves have been made so far.

Also problematic is the Japanese government’s reluctance to hold open debates about a Taiwan crisis because it does not want to sour ties with China. But there is a significant rift among politicians and experts in Japan over the Taiwan issue.

Tokuhiro Ikeda, a senior fellow at Harvard University’s Asia Center, emphasized the role the private sector should play.

“The National Security Strategy aims to deter crises, too,” Ikeda said. “It is essential for the media and experts to project what the government cannot say publicly based on disclosed information and other sources for deeper discussions.”