The upbeat remarks by visiting Japanese Prime Minister Shinzo Abe and Chinese leaders in Beijing yesterday will no doubt heighten expectations of a rapid thaw in bilateral ties chilled by wartime history. Mr Abe told Premier Wen Jiabao yesterday that he believed bilateral relations would enjoy sunny skies after the rain. President Hu Jintao hailed Mr Abe's visit as a turning point in ties, while Premier Wen talked about the irresistible trend towards a friendly, co-operative relationship. But optimism will be misguided if one believes Sino-Japanese ties will be plain sailing from now on. The outstanding issue that has chilled the relationship for the past five years remains unresolved and it is very likely to come back to sour relations between the two Asian giants. There is little doubt that the leaders of both countries are keen to turn over a new leaf, as illustrated by the haste with which this historic visit was arranged. Mr Abe's visit came less than two weeks after he took office, making him the first Japanese postwar prime minister to choose China as the destination of his first overseas state visit and the first since 2001 to hold a summit in Beijing. The Chinese side showed its eagerness by having the country's top three leaders including Wu Bangguo , chairman of the National People's Congress, meet Mr Abe on the opening day of the important annual plenary session of the Communist Party's central committee. No doubt, North Korea's threat to conduct a nuclear test also hastened the meeting, with some mainland official sources believing Washington also exerted pressure on Mr Abe to improve ties and work closely with China and South Korea to contain North Korea's nuclear ambitions. But a breakthrough in the bilateral relationship based on Mr Abe's 'constructive ambiguity' over Tokyo's controversial Yasukuni Shrine is not going to hold for very long. Both Beijing and Seoul refused to hold summits with Mr Abe's predecessor, Junichiro Koizumi, because of his public pilgrimages to the Yasukuni Shrine, which honours Japanese war dead including convicted war criminals from the second world war. The grandson of a suspected war criminal, Mr Abe is known for his hawkish nationalistic views, including promises to rewrite Japan's pacifist constitution, and he openly supported Mr Koizumi's trips to the shrine. Chinese officials claimed Beijing reached an agreement with Tokyo over the shrine issue, giving an explicit impression that it had gained important concessions from Mr Abe, in the form of an agreement not to visit the shrine, as a condition for his visit to China. But Japanese officials have denied Mr Abe made any compromises and said he would maintain the policy of not saying whether he would visit the shrine or not. In fact, it was Beijing which made the important compromise. By meeting Mr Abe, it has quietly dropped its demand that the Japanese prime minister must promise to stop visiting the shrine as a precondition for a summit meeting. But this is a good move on the part of Beijing. By insisting on the demand, Beijing had itself in a tight corner with little room to manoeuvre. In contrast to the western analysts who believe Mr Abe could be the man to put bilateral ties back on track, many mainland officials and analysts are less optimistic. Their feelings are reflected in a report carried yesterday by a leading mainland newspaper, the Guangming Daily, which criticised Mr Abe's ambiguity over the shrine issue and warned it was very dangerous for Japan's ties with China and South Korea.