(February 6, 1964)
Mao Zedong (hereafter referred to as Mao): We’ve had some achievements in building the atomic bomb too!
Qian Xuesen (hereafter referred to as Qian): I have heard something to that effect.
Mao: I’m afraid it’s more than just hearing something.
Qian: Regarding the atomic bomb, it is indeed only something I have read about. My research is on delivery vehicles.
Mao: Yes. You’ve developed one with a range of a thousand kilometers, and in the future you’ll develop one with a range of two thousand kilometers, which should be about enough.
Qian: Some of the bases in the U.S. imperialists’ crescent-shaped encirclement in Southeast Asia are at a distance of two thousand eight hundred kilometers.
Mao: Can it reach Hawaii?
Qian: Hawaii is farther still, more than four thousand kilometers.
Mao: We must always develop defense. Dig tunnels, get underground, and we won’t be afraid of it.
Qian: We are following the Chairman’s instructions, first organizing a small group of scientific and technical personnel to prepare to study methods and technical approaches for defense against ballistic missiles. It appears that during the Third Five-Year Plan, due to insufficient technical conditions, we still cannot commence design work.
Mao: Where there is a spear, there must be a shield. Assign a small number of people to study this problem specifically. If five years won’t do, then ten; if ten years won’t do, then fifteen. It must be developed eventually.
[l]
This is part of a conversation between Mao Zedong and the famous scientists Qian Xuesen, Li Siguang, Zhu Kezhen, and others.

Data photo