Why was Qian Xuesen locked up in America for half a year?

House arrest is not half a year but five years. Due to Chinese demands and pressure, after five years of detention investigation, the United States finally confirmed that Qian Xuesen's information and value had no significant influence on them, and then sent him back to the motherland with the permission of President Eisenhower. In fact, Qian Xuesen's achievements prove that the United States' choice is wrong. Qian Xuesen's achievements are equivalent to five naval divisions of the US military.