Qian Xuesen was stripped of his security clearance in 1950, as a result of the Red Scare, meaning he couldn't work on his areas of expertise any more. He tried

Qian Xuesen was stripped of his security clearance in 1950, as a result of the Red Scare, meaning he couldn't work on his areas of expertise any more. He tried to leave the US, but was arrested on his way out and kept under house arrest for 5 years. That's the thanks he got for helping found the US rocketry program, so when he was released, he founded China's rocketry program.