With Friday marking one year since Russia's invasion of Ukraine, calls have been mounting for Japan, this year's chair of the Group of Seven countries, to take the lead in global support for Kyiv, including postwar reconstruction.

Foreign affairs experts have also urged Japan, the only nation to have been attacked with atomic bombs, to show its unwavering commitment to tackling nuclear threats at a G-7 summit in Hiroshima in May, amid fears that Russia could use nukes in the war.

So far, Japan has only offered nonmilitary assistance to Ukraine due to restrictions on the provision of weapons, while Western countries have expanded their lethal aid, including battle tanks.

Prime Minister Fumio Kishida announces Japan's decision to provide $5.5 billion in additional financial aid for the reconstruction of Ukrainian infrastructure destroyed by Russia, at a symposium in Tokyo on Feb. 20, 2023. (Kyodo)

As G-7 chair, Japan's key role is to solidify unity on the provision of nonlethal support for Ukraine, while trying to prevent Russia from launching a nuclear attack on its neighbor, the experts said.

Since the start of the war on Feb. 24, 2022, the government of Japanese Prime Minister Fumio Kishida has imposed tough sanctions on Russia in line with the other G-7 nations -- Britain, Canada, France, Germany, Italy and the United States, plus the European Union.

Among the punitive steps are asset freezes on President Vladimir Putin and Russia's central bank, revocation of the country's "most favored nation" trade status, and export bans on cutting-edge technology.

Japan has also offered financial support to Ukraine worth $600 million, along with humanitarian and medical supplies as well as defense equipment such as bulletproof vests and helmets. Tokyo has also pledged an additional aid of $5.5 billion for Kyiv.

But Tokyo has not delivered weapons to Ukraine as a law enacted in accordance with Japan's postwar pacifist Constitution does not allow the Self-Defense Forces to provide arms to foreign forces without compensation.

In addition, the Japanese government's "three principles" on overseas transfers of defense equipment and technology effectively ban weapons exports, except for joint development or production projects with another country.

Under the circumstances, what Tokyo can do is exhibit its leadership in nonmilitary areas, such as helping to rebuild Ukrainian infrastructure, said Shinji Hyodo, director of the Policy Studies Department at Japan's National Institute for Defense Studies.

"Japan has gained know-how on reconstruction work based on its past experience of natural disasters, including earthquakes and tsunami," said Hyodo, a Russia and international relations expert.

As an example, Hyodo cited collaboration between Japan and Cambodia in supporting the clearance of Russian landmines and unexploded bombs in Ukraine. Training for the work already started in January.

Ukrainian government officials visit a company that produces mine detection devices in Yamanashi Prefecture, west of Tokyo, on Jan. 24, 2023. (Kyodo)

Japan has contributed to demining efforts in Cambodia, where millions of landmines are believed to have been laid during the 1970-1991 civil war in the Southeast Asian country.

"Western nations are now focusing on how to bring the war to an end by beefing up their military support for Ukraine, but it is difficult for Japan" to follow suit, Hyodo said, adding Tokyo should act in anticipation of a termination of hostilities.

The United States, Britain, Germany and other European countries recently decided to send tanks to Ukraine, amid speculation that Russia could launch a large-scale offensive in the spring.

The potential escalation may be linked to Russia's presidential election scheduled for March 2024, when Putin would be eager to tout his "military achievements," Hyodo said.

If Ukraine is able to utilize the tanks provided by the West to recapture territory occupied by the Russians, Putin could consider using nuclear weapons, he said.

"For Ukraine to win, Russia must lose. The G-7 states and other nations should have a common understanding on how the war can be ended without the use of nuclear weapons by Russia," Hyodo added.

This year's G-7 summit is slated to take place for three days from May 19 in the western Japan city of Hiroshima, which was devastated by a U.S. atomic bomb in August 1945.

Masafumi Ishii, a special adjunct professor at Gakushuin University, said Japan can take the initiative on the Ukraine crisis at the G-7 summit, given that the leaders would sternly warn against any use of nuclear weapons.

Ishii, a former Japanese ambassador to Indonesia, also highlighted the importance of Tokyo ensuring that the other G-7 members also pay attention to the security situation in the Indo-Pacific region, where China has been intensifying its military activities.

Kishida has warned that "Ukraine today may be East Asia tomorrow," in a veiled reference to China's territorial ambitions, including its claim to democratic Taiwan, which Beijing regards as a renegade province to be reunified with the mainland, by force if necessary.

At the summit, Japan and the other G-7 countries "should send a message that any attempts to change the status quo by force are unacceptable in the East and South China seas, and the Taiwan Strait," Ishii said.

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