Yang Jiechi photo:CGTN

Old problems in China-Japan relations are intertwined with new ones, and the challenges cannot be ignored if the two countries wish to have "healthy" relations, senior Chinese diplomat Yang Jiechi told Japanese national security chief Takeo Akiba on Tuesday over the phone. 

The call came as Tokyo is "adopting the most vicious China-policy since ties were normalized," as Japan keeps flirting with China's hot-button issues, such as the Taiwan question, and is reportedly aiming to send an active-duty defense official to Taiwan island to strengthen information-gathering capabilities.

The call, according to experts, serves as a warning to Japan to dial down its provocative actions on China's hot-button issues, and also implies the necessity of stabilizing China-Japan relations amid a hostile atmosphere between Beijing and Washington. 

Yang, a member of the Political Bureau of the Communist Party of China (CPC) Central Committee and director of the Office of the Foreign Affairs Commission of the CPC Central Committee, spoke on the phone with Akiba on Tuesday, saying both nations should "grasp the right direction, uphold win-win cooperation, focus on the long term, enhance security and build mutual trust." 

Yang also said both countries should work together to ensure "stable, healthy and resilient" relations in the next 50 years, and "jointly maintain regional peace and prosperity."

According to the readout of China's Foreign Ministry, Yang made clear to Akiba China's stance on issues regarding Taiwan, Hong Kong and the Diaoyu Islands. 

Akiba vowed to deepen cooperation with China and strengthen communication on sensitive bilateral and hot international issues. 

The call came as Japan is closely tagging along with US moves to counter China in the region. Tokyo recently ruffled Beijing's feathers by upping the ante on the Taiwan question, China's hot-button issue, hyping the China threat theory in the Asia-Pacific region, and preparing to open the door of this region to NATO.

Yang's remarks were seen as a warning, which showed China's deep concern and solemn stance on Japan's recent moves, Liu Jiangyong, vice dean of the Institute of Modern International Relations at Tsinghua University, told the Global Times on Tuesday. He noted that it can be seen as a signal to Japan that "Don't say I did not send a warning."

Observers said it is necessary to stabilize China-Japan relations against the backdrop of deteriorating China-US ties. The golden anniversary of ties can be an opportunity for both sides to push relations closer, they said but noted there should not be high expectations on Japan. 

Among the latest provocation, Japan's ruling Liberal Democratic Party (LDP) held a meeting on Monday, in which a draft of the Basic Policy for Economic and Fiscal Operation and Reform, known as the "Gutai Policy," was revealed, Japan's Kyodo News reported. A rare reference to the "importance of peace and stability in the Taiwan Straits" was added, but it did not mention the increase in the defense budget. 

The draft was expected to be finalized at Tuesday's cabinet meeting.

Lian Degui, director of the Department of Japanese Studies at Shanghai Institutes for International Studies, told the Global Times that it is unnatural to add the Taiwan question into a policy document that focuses on the economy. 

Experts said it signals Japan's long-term plan of interfering in the Taiwan question, which poses a severe provocation to China's domestic affairs, and will face a strong and fierce response from Beijing. 

Another warning sign came after media reported that Japan's Ministry of Defense was reportedly planning to send an active-duty defense official to Taiwan from June to September to strengthen information-gathering capabilities, according to local website Sankei. Yet the information has not been confirmed by Japanese officials. 

Xiang Haoyu, a research fellow at the China Institute of International Studies, said that if confirmed, it will break the current framework of Japan's relations with the island of Taiwan, as the political document between China and Japan clearly states that Japan cannot violate the one-China principle and can only maintain non-official relations with Taiwan. 

Experts believe such a move is an edge ball, as the defense official who would be sent is a civil official and sending a civil official is less provocative and helps gather information. Although the information has not been confirmed, they suggest China should react strongly to this move, as it is a "sausage cutting" move of Japan to send incumbent civil officials first and then, if they are not met by a strong reaction from the Chinese mainland, send military personnel or even increase the number of people stationed in the island. 

Japan is also eyeing NATO to back its ambition to seek "autonomous defense" and expand its defense capacity. Japanese Prime Minister Kishida Fumio is reportedly preparing to attend the NATO summit later this month, and will be the first Japanese leader to participate in the meeting of the military alliance. 

Fu Qianshao, a Chinese military aviation expert, told the Global Times that we should pay close attention to Japan's move, because if the information is confirmed, it signals that the US and Japan are preparing military moves in this region. 

The Russia-Ukraine crisis taught us that even if NATO countries don't send troops to Ukraine, it did not stop them from sharing intelligence, and such moves exert a significant impact on the battlefield, said Fu. 

China has tools in its tool kit to cut military connections, said Fu, including destroying land- and sea-based infrastructure, electromagnetic detection, and electronic interference.