Tsien was observed in his office writing long letters in Chinese, or talking about plans for his life in China. "I remember Tsien talking about his imminent departure with regrets and, occasionally, with bravado, which is normal for almost any person in that position," remembered S. S. Penner, then an assistant professor in jet propulsion at Caltech. "He certainly had mixed feelings about going, and fundamentally he was not at all happy about going."
Almost everyone who knew him felt that Tsien's departure would be a tremendous loss to the country. And indeed, forty years later, the U.S. government would be faced with one of the supreme ironies of Cold War history. It had accused Tsien of being a member of the Communist Party when there was no clear evidence that he had ever been a member, and to punish him had deported him to Communist China . . . where Tsien was credited with revolutionizing the Chinese ballistic missile program. Who was accountable for this situation?
The largest share of the blame rests on the U.S. government at the time. Initially, it had every right to be suspicious of Tsien -- to cancel his clearance, to