Sino-US cooperation? (Question #5)

There is some evidence in sources A-C that the changes in relations between USA and the PRC in 1971 were less fundamental than is sometimes supposed. In source A, it is mentioned that China's foreign policy is still very hostile towards other countries. It is said that they are booth aloof and suspicious. Source B initially seems to support the idea that the change in Sino-US relations was great, but later on it goes on to mention that the relationships between the countries had been suspended for twenty years. Source C mentions that three-corner diplomacy was advantageous to the United States, showing that the US is still sticking to their own ways. There is façade of agreement, but really every country is still looking out for their own interests.