Japan¡¯s heavily trailed decision to discharge treated water from the Fukushima No. 1 nuclear plant into the ocean has caused significant friction with China, damaging the chances of a much-awaited detente.

As the two countries celebrate the 45th anniversary of the signing of the Treaty of Peace and Friendship, Japan is now bracing for a new period of wide-ranging tensions with its giant neighbor.

In the direct aftermath of the start of the discharge last Thursday, Beijing immediately enforced a retaliatory ban on all Japanese fish imports, while reports of harassing phone calls to businesses, schools and government facilities across Japan made headlines in the country over the weekend.

In response to the flare-up, Japan¡¯s vice foreign minister, Masataka Okano, summoned Chinese Ambassador to Japan Wu Jianghao on Monday and urged the Chinese government to stop spreading misinformation, underlining the scientific evidence proving that the discharge has a negligible impact on the environment.

The tit-for-tat dragged on after the Chinese Embassy released a Monday evening that lambasted Japan¡¯s obstinate and selfish behavior and lamented that Chinese missions in Japan had also been receiving similar calls from within the country.

On Tuesday, while commenting on an incident where stones were hurled at the Japanese Embassy in Beijing, Chinese foreign ministry spokesman Wang Wenbin said that the Chinese authorities had ¡°made clear their solemn position on Japan¡¯s so-called concerns,¡± but blamed the nation¡¯s ¡°irresponsible behavior¡± for the backlash.

A Japanese government spokesman didn¡¯t comment on Wang¡¯s remarks Wednesday, instead stating that Japan may raise a formal complaint to the World Trade Organization over the import ban.

In the past few months, signs of a steady improvement in bilateral ties had slowly begun to surface.

In April, Foreign Minister Yoshimasa Hayashi flew to Beijing to meet with his counterpart Qin Gang ¡ª the first visit to China by a Japanese foreign minister in over three years. Three months later ¡ª after Qin essentially disappeared from public view over the summer ¡ª Hayashi and Beijing¡¯s top diplomat Wang Yi held bilateral talks on the sidelines of an ASEAN-related meeting in Indonesia.

Consultations between the country¡¯s top envoys are often a prelude to meetings at higher levels.

Earlier this month, Chinese diplomats informed Japan about the possibility of hosting talks between Prime Minister Fumio Kishida and Beijing¡¯s Premier Li Qiang during an upcoming ASEAN summit in early September, but reportedly nothing has been decided yet.

After a successful rapprochement with South Korea, Kishida has repeatedly expressed his hopes of traveling to China for a bilateral meeting with Chinese President Xi Jinping.

In an effort to set the stage for top-level talks, Kishida asked Komeito¡¯s leader Natsuo Yamaguchi to deliver Xi a...