While cyberwarfare is seen as the next major security threat, the Self-Defense Force is hampered by limited staffing and legal questions.

Although the SDF's cyberwarfare capabilities pale in comparison to the U.S. military's, Japan can rely on its ally in the event of an attack. Japan and the United States have participated in a joint simulation exercise for such a scenario.

U.S. Secretary of State Mike Pompeo made it clear at a joint news conference in April 2019 with his Japanese counterpart and others that Washington was prepared to support Tokyo should it come under a cyberattack.

“The United States and Japan affirmed that international law applies in cyberspace and that a cyberattack could, in certain circumstances, constitute an armed attack under Article 5 of the U.S.-Japan Security Treaty,” Pompeo said after a meeting in Washington, D.C.

His comment meant that damage to important social infrastructure or harm to Japanese civilians caused by hackers would be sufficient justification for the U.S. military to launch a counterattack.

ORIENT SHIELD TESTS CAPABILITIES

In September 2019, the SDF cooperated with the U.S. military in a training exercise known as Orient Shield, centered mainly in the main southern island of Kyushu, while the U.S. Army was also conducting another exercise called Cyber Blitz.

That marked the first time the SDF was involved in a multidomain operation in which the U.S. military brought together elements of ground combat tactics with cyberwarfare.

A Defense Ministry source said, “We were able to confirm how to maneuver our respective units while also having each nation protect their own computer systems.”

But for many reasons, the SDF’s cyberwarfare capabilities are in the starting blocks compared to the U.S. military. 

In 2018, the U.S. military elevated a sub-group into the Cyber Command, one of 11 unified combatant commands under the U.S. Defense Department.

U.S. Cyber Command is made up of 133 units over all the military services with total staffing of about 6,200. Not only is it in charge of protecting the U.S. military’s computer networks, but it also has a unit that utilizes cyberwarfare to support conventional forces.

In contrast, the SDF established a cyber defense unit in 2014. The unit now has about 220 members, meaning it is dwarfed by its U.S. counterpart.

In the background to the increasing cooperation between the two nations are the moves being made by China. Beijing recognizes the U.S. military's overwhelming advantage in conventional forces so it has focused on countering Washington in the cyber and space domains.

“We will strike at the weaknesses of the U.S. military that depends on advanced technology such as computer networks and satellites,” said a researcher at a think tank affiliated with the Chinese military.

In summer 2019, a strategic support force participated in one of the largest simulation exercises involving a military incident connected to Taiwan. The cyber unit was in charge of hacking to destroy important infrastructure such as power plants

With Chinese President Xi Jinping having called for an integration of the military and private sectors, the force is also cooperating with employees of communications companies and individual hackers often referred to as the cyber militia.

One hacker said there were several hundreds of thousands of individuals making up the cyber militia.

LEGAL QUESTIONS REMAIN IN JAPAN

Many legal barriers have to be overcome in Japan before the SDF can improve its cyber capabilities or strengthen cooperation with the U.S. military. A major reason is the unique characteristics of cyberspace.

During a conventional attack, spy satellites and radar can quickly pinpoint where the attack came from. But that identification is much more difficult for cyberattacks. It is also much more difficult to determine what cyberattacks constitute an “armed attack” on Japan.

No international treaties either under the U.N. or at other multilateral levels exist in relation to cyberattacks.

The major powers such as the United States, Russia and China are engaged in espionage campaigns by transmitting computer viruses to foreign nations.

At the same time, those nations are also proceeding on a daily basis with identifying the type and source of computer viruses sent by enemy nations as one way to defend against large-scale cyberattacks.

On the other hand, the activities of the SDF are much more limited.

Defense Minister Taro Kono has said that even in cyberspace an “exclusively defensive posture” was still the guiding principle and that there was no change in the government position of obeying the relevant domestic and international laws.

There is also a provision in Japanese Criminal Law that bans the creation of computer viruses. Moreover, trying to identify the source of a cyberattack might lead to violating Article 21 of the Constitution, which guarantees secrecy of all forms of communication.

“Even if we were able to find the computer server used by the hacker, we could not do anything further,” said a source in a public safety commission.

But the U.S. position puts it on a different playing field.

Paul Ney, general counsel for the Defense Department, said at a conference in March, “The department believes there is not sufficiently widespread and consistent state practice resulting from a sense of legal obligation to conclude that customary international law generally prohibits such nonconsensual cyber operations in another state’s territory.”

In contrast, Japan in its latest National Defense Program Guidelines said the SDF would “strengthen its cyber defense capability, including the capability to disrupt opponent’s use of cyberspace.”

But the guidelines added that such capability would only be used “during an attack against Japan.”

Masahiro Kurosaki, an associate professor of international law at the National Defense Academy, pointed out the difficulties of a joint response between the SDF and the U.S. military against a cyberattack.

He said the U.S. military utilized cross-border cyber-activities even in the preliminary stages of an armed attack while for the SDF “similar activities would be difficult until the attack was designated as an ‘armed one.’ ”

A high-ranking Defense Ministry official also raised doubts about whether the SDF would be able to support the U.S. military should its U.S. Forces Japan or U.S. Indo-Pacific Command suffer major damage from a cyberattack.

Japan could exercise its right to collective self-defense in such a situation because it would face a crisis threatening its very existence.

But the Defense Ministry official said, “There are many issues in terms of both the SDF’s capability and legal questions so we might not be able to meet the expectations of the United States.”

Another issue facing Japan is how to become involved in the writing of international rules related to cyberwarfare.

Meanwhile, Motohiro Tsuchiya, a professor of international politics at Tokyo’s Keio University, said there was no distinction between ordinary times and war under a cyberattack.

“There is no telling who will start an attack and from where,” he said. “It is also difficult to determine if such an attack involves a nation or is simply a crime by an individual hacker.”

He added that even in ordinary times it would be difficult for Japan to copy other nations and transmit computer viruses to the networks of other nations because such actions would violate domestic law.

But he called the creation of a cyber training venue shut off from external computer networks where SDF members could try their hand at attacking and defending in cyberspace a "half step forward."

“There is a need for calm discussions from ordinary times to put together a legal framework for such capabilities,” Tsuchiya said.

(This article was written by Senior Staff Writer Taketsugu Sato, Senior Staff Writer Takateru Doi and Senior Staff Writer Kenji Minemura.)