"In order to stress the main points, we should give up some things of secondary importance. One must lose one thing in order to gain another. If we attend to too many things at the same time, we shall end up by developing nothing. In modernizing our army, we should import some necessary and advanced technological equipment. However, ours is a big but developing country. It will not do to rely on purchasing advanced technological equipment to achieve the modernization of national defense. Nor can we afford it. We may purchase some weapons and equipment but they will not necessarily conform to the specific conditions in our country, such as topography and weather. We should base ourselves on independence and self-reliance and rely on our own strength to develop weapons and equipment. We have developed and produced sophisticated strategic weapons, such as atom bombs, hydrogen bombs, and long-range guided missiles, as well as excellent conventional weapons for self-defense."
January 1, 1970
https://en.wikiquote.org/wiki/Yang_Shangkun