【明報專訊】SINO-JAPANESE relations have taken an abrupt turn in recent months following the escalation of the rivalry between China and the US. The Japanese government has accused Chinese public service ships of entering waters off the Diaoyu Islands increasingly frequently. It has also adopted an increasingly high profile on the issue of the South China Sea and Hong Kong. What is more, it is reported that the Japanese government intends to join the "Five Eyes" intelligence alliance dominated by the UK and US. It is even understood that Japan will allow the US government to deploy midrange missiles in its land. In the meantime, Japanese cabinet members have visited Yasukuni Shrine for the first time in four years, and Prime Minister Abe Shinzo has heaped praise on former Taiwanese President Lee Teng-hui, who passed away recently. Each of these gestures threatens China's bottom line. In contrast with past deteriorations in Sino-Japanese relations, which were caused by sudden events, the recent downward trend in Sino-Japanese relations has been caused by the international situation and changes in Japan's political arena in the post-Abe era. As this downward trend appears to be long-term and structural, it is likely to have profound and far-reaching consequences for the entire Northeast Asia.