Less than a month later, Pei suspended his work at Harvard to join the National Defense Research Committee, which coordinated scientific research into US weapons technology during World War II.
Kurang dari sebulan kemudian, Pei berhenti bekerja di Harvard dan kemudian bergabung dengan National Defense Research Committee, yakni badan yang mengoordinasikan penelitian teknologi senjata AS selama Perang Dunia II.