Westwick replies: I thank Harrison Schmitt for his firsthand knowledge of events. Existing evidence suggests that by 1980 President Ronald Reagan had learned about new concepts for missile defense, including Edward Teller’s, from various sources, but that Teller himself was frustrated by his lack of personal access to the president until September 1982. His July 1982 letter was an effort to provide his views. Further research may indeed clarify this chronology.

I agree that Reagan—and most others in the US—viewed the Strategic Defense Initiative as purely defensive, and furthermore that his personal offer to share SDI technology was sincere. My point is that the Soviets did not believe him.