Recently Asahi News reported the following:
海上自衛隊の練習艦隊が香港に寄港しようとして中国政府に断られたことが１５日わかった。日本政府関係者が明らかにした。公式には理由は示さりていないが、亡命ウイグル人組織「世界ウイグル会議」のラビア. カーディル主席の入国を日本が認めたことなどに中国側が不満を示したという。香港に寄港しようとしていたのは、海自の遠洋練習航海部隊。練習艦「かしま」「しまゆき」、護衛 艦「ゆうぎり」で編成し、約７００人を乗せ４月に東京. 晴海を出航。東南アジア、中東、欧州など１３力国を回って９月上旬に帰国する予定だ。香港への寄港は当初の計画になかったが、日中間で防衛交流が進んだことを踏まえ、８月末から９月上旬にかけて寄港して軍関係者と交流したい意向を中国側に伝えた。しかし、中国政府は１２日、北京の日本大使館に「敏感な問題があり、寄港を認める雰囲気ではない。受け入れは難しい」と返答した。関係者によると、日本政府が７月末、新疆（しんきょう）ウイグル自治区ウルムチで起きた騷乱の扇動者と中国が非難するカーディル氏入国を認めたことを挙げ、台湾の李登輝元総統が９月に訪日することにも不快感を示した。
On 15th, it was learned that China had refused to allow Japan's Sea Defense Force training fleet to visit Hong Kong, according to people who had connection with the Japanese government. Although no formal reasons were given, it was speculated that China wanted to show its displeasure because the chairman of the 'World Uighur Conference' had been allowed to visit Japan. It was Japan's Sea Self Defense Force ocean going training fleet that wanted to visit Hong Kong. It consisted of two training ships and one escort ship carrying about 700 sailors and had departed from Tokyo in April. It would visit 13 countries in south east Asia, Middle East, Europe and return to Japan in early September. The plan to visit Hong Kong was based on the wish to promote Chinese-Japanese defense exchange, and Japan's intention to visit Hong Kong by the end of August and early September had been conveyed to the related Chinese military personnel. But on 12th, China informed Japanese consulate in Beijing that 'there is some sensitive issue involved, and the situation is not conducive to allow such a visit. There is difficulty to give the permission'. According to people who had connection with the matter, China wanted to show its displeasure because Qadir, who had been accused by China as the agitator of the riot that happened in Urumqi in the Uighur Self-ruling Region in Sinkiang, was allowed to visit Japan in July. Also Japan had given permission to the former Taiwan President Lee Teng-hui to visit the country in September.
Diplomacy is a complicated issue. After reading the above, I wonder if Japan's foreign policy decision would yield to the pressure from China.