Intelligence sources allowed the United States to know about and warn its allies at least two days before China's top-secret missile-interception test early last year, according to confidential diplomatic cables released by whistle-blower WikiLeaks. A military expert said the cables showed the US had significantly extended the reach of its intelligence network on the mainland since the surprise launch of a Chinese anti- satellite missile in 2007. A classified cable from the US secretary of state to diplomats in allied countries on January 9 last year indicated that Washington knew details of the sensitive missile test days before the launch, including the locations of two launch sites, the missiles' models, the purpose of the test and the date of the event. The cable, sent to US embassies in Australia, Britain, Canada and New Zealand, ordered ambassadors to deliver secret information about the imminent intercept flight-test on January 11. 'Washington estimates that China may be planning to use its SC-19 missile to conduct an intercept flight-test against a CSS-X-11 medium-range ballistic missile that could happen within the next several days,' the cable said. 'We anticipate that the SC-19 will launch from the Korla Missile Test Complex [a new location for SC-19 activity] in western China. The CSS-X-11 will launch from the Shuangchengzi Space and Missile Centre, approximately 1,100 kilometres east of Korla . 'Action addressee posts should co-ordinate closely with host governments prior to, during and after China conducts the next SC-19 flight test, to ensure that all necessary officials in Australia, Canada, the United Kingdom and New Zealand have timely and complete information regarding China's activities.' The US warned its allies that the SC-19 was used 'previously as the payload booster for the January 11, 2007, direct-ascent anti-satellite intercept of the Chinese FY-1C weather satellite', which surprised the international community and prompted fears about a new arms race in space. The US expressed its hope that allies would remain silent before the test, to protect 'sensitive intelligence sources and methods', according to the cable. Beijing launched the test as expected on January 11 of last year and announced its success through Xinhua the next day. Xu Guangyu, a retired PLA general and a researcher with the China Arms Control and Disarmament Association, said the cable, if authentic, indicated the possibility that US intelligence had reached into the heart of the Chinese government or military, or both. Otherwise it would not have been able to obtain the information, deemed a top state secret. Xu said the US had been closely monitoring China's military bases using its best spy satellites. And with the help of high-definition cameras and remote sensing technology, the US military would be notified in the event of any unusual activity, he said. But possessing the most sensitive information, such as the missile's model and the launch day, showed that someone might have tipped off the US from within, betraying their country, Xu said. In a classified cable to the US embassy in Beijing on January 12, the day after the launch, Washington instructed its diplomats to keep their lips sealed on what they knew about the launch and the missiles. 'This test is assessed to have furthered both Chinese ASAT [anti-satellite weaponry] and ballistic missile defence technologies. 'Due to the sensitivity of the intelligence that would have to be disclosed to substantiate the US assessment, the US Government in its demarche to the PRC Government will not associate the January 2010 SC-19 intercept flight-test with past SC-19 ASAT flight-tests,' the cable said. Though many media organisations and analysts suspected the link between the launch last year and the anti-satellite test three years ago, the US government has never acknowledged the link and said that China had kept it in the dark. Xu said the US played two stacks of cards with China. On one hand, it pressed the Chinese government for more military transparency, but on the other hand, it reduced its own transparency. He said that if China could no longer keep secret its missile launches, it would not be able to launch a surprise attack on the US. But he noted that China was monitoring missile activities in the US, too. 'The advancement of technology lets big countries keep a close eye on one another,' Xu said. 'But judging from the cables, I suspect that the US was showing off its intelligence might to its allies. 'They did not say it explicitly but made their meanings very clear - that you'd better follow my footsteps because I know more than you do.'