Taiwan will declassify a set of confidential documents on a failed military attempt by the late Kuomintang generalissimo Chiang Kai-shek to recover the mainland in the 1960s. From the start of next month, visitors, including those from the mainland, will be allowed to visit Back Tzuhu, which has housed the secrets of Chiang's failed mission for nearly five decades. The seven-hectare, crescent-shaped Back Tzuhu has been a restricted section of the Chiang Kai-shek Mausoleum in Tzuhu in the northern county of Taoyuan, according to previews of the classified documents given to media yesterday. The site served as a wartime command centre for Chiang during Project Kuokuang, or the Project of National Glory, during the 1960s. Sensing the right moment had arrived as the Communist government botched its economy with the disastrous 'Great Leap Forward', the outbreak of the Vietnam war and the prospect that the mainland might soon have a nuclear weapon, Chiang decided that the need to launch an counterattack and recover the mainland, which had been lost at the end of a bitter civil war in 1949, was urgent. He ordered the construction of air-raid shelters and five military offices at Back Tzuhu, which served as a secret command centre in April 1964. The order was made without the knowledge of the United States, which was against the move. All preparations were kept as secret as possible to avoid US detection. But the mission got off to a bad start. On June 24, 1965, dozen of soldiers died during a drill planned to simulate a Communist attack on a major naval base in southern Taiwan. On August 6, 1965, two major naval vessels assigned to transport special operation troops for a reconnaissance mission along the mainland's coast were intercepted and sunk by naval vessels off Dongshan Island near Fujian province. The troops were virtually annihilated, with about 200 killed. In November the same year, Chiang ordered two other naval vessels, the Shan Hai and the Lin Huai, to pick up wounded soldiers from Makung and Wuchiu, offshore islands of Taiwan. The vessels were attacked by 12 mainland ships, and the Lin Huai was sunk by two torpedoes, with some 90 soldiers killed. In one of the documents, the Kuomintang military attributed the setbacks to the Communists' effective reconnaissance work, but according to former Taiwanese navy commander Yeh Chang-tung, both the US and Beijing were fully informed of the military plans beforehand. The US was also reported to have strongly opposed the recovery project and had tried to check the secret base many times. Because of the US objection, Chiang was unable to obtain sophisticated weapons to launch a counterattack. The sinking of the naval vessels seriously eroded Chiang's confidence that he cold retake the mainland, and the project was reduced in scale year after year and was ignominiously dropped in July 1972.