and Chris Buckley CHINA and Japan agreed amid fanfare this week that friendly ties are vital, but a pair of pandas and ping-pong diplomacy aren't enough to erase the deep distrust that could yet derail the detente between the Asian rivals. Chinese President Hu Jintao's rare state visit was meant to cement warming relations between two countries that are closely linked by trade and investment but long divided by a bitter wartime past and regional rivalry. Stronger bilateral ties would help their economies - China is Japan's biggest trading partner, and Japan is a big source of much-needed investment and technology in China - but it could also shore up regional security. "The revival of Asia cannot do without cooperation between China and Japan," Hu said in a speech at Tokyo's Waseda University on Thursday in which he reiterated his consistent message that the two countries must look forward, not back. Hu's speech mentioned - but did not dwell on - Japan's 1931-45 military aggression in China, a stark contrast to the harsh rebukes over history delivered by predecessor Jiang Zemin during the last state visit by a Chinese leader a decade ago. Eager to court a Japanese public suspicious of China's rising clout, Hu also offered to lend two pandas to a Tokyo zoo and showed off his ping-pong prowess, but not everyone was impressed. "The president came and said the relationship is friendly, but it kind of seems that's just on the surface," said Japanese salaryman Katsushi Harasawa, 24. "Things don't change so easily." That was also the nearly unanimous assessment by experts in both Beijing and Tokyo of Hu's visit, set to end on Saturday with sightseeing at temples in Japan's ancient capital of Nara. "Now official relations are very warm," said Huang Dahui, a Japan expert at Renmin University in Beijing. "But in fact, the biggest obstacle to better ties is public distrust on both sides." Anti-Japanese protests in China have subsided since the sometimes-violent demonstrations seen in 2005, but Chinese nationalism has been galvanized by criticism of Beijing's human rights record in Tibet ahead of the Beijing Olympics in August. Zhang Liangui, an Asian security researcher at the Central Party School in Beijing, a think-tank, said anti-Japanese sentiment still constrained Chinese leaders despite official efforts to persuade the public of the benefits of better ties. "The Chinese government must always take into account this popular distrust. It can't go too far ahead of popular feeling, otherwise it will face trouble," he said. In Japan, right-wing activists have seized on Tibet to denounce China, which they see as a threat, and Hu's visit was marked by protests by both nationalists and proponents of Tibetan independence. China's rise also stirs anxiety among ordinary Japanese. "Japan looks at China as a very important economic partner," said Koichi Nakano, a professor at Tokyo's Sophia University. "But at the same time, there is uneasiness about the very real possibility that China will take over Japan as the economic power in the region," Nakano added. That mutual skepticism could yet deter negotiators from concessions needed to resolve specific rows, including a festering feud over East China Sea gas fields. The dispute symbolizes more than an argument over maritime gas rights by the two energy-hungry economies. "The East China Sea dispute has become so sensitive because it distils both sides' biggest concerns about territory, sovereignty and security," said Huang, the Beijing expert. The two leaders said after their summit on Wednesday that a resolution was in sight, but gave no details. Japan's trade minister on Friday denied reports that, in what would be a major concession, China had agreed to develop jointly a site that lies on a median line Tokyo says marks the border between the two countries' exclusive economic zones. "If Japan has something like that in mind, many people here will be opposed. Any issue involving Chinese sovereignty and national dignity is too important," said Tong Zeng, a major organizer of anti-Japan protests in China in 2005. Fukuda needs China to bend, not least because of his already sagging public support rates, a trend-line that has many pundits predicting he could lose his job later this year, perhaps to be replaced by right-leaning former foreign minister Taro Aso. The deep chill of the recent past may be unlikely to return post-Fukuda, but no one expects problems to disappear soon. – Reuters __