"China is poor and our military is backwards, I agree. But we have our traditions, you know. And for quite some time, using inadequate and miserable equipment, we have cultivated the art of defeating well-armed enemies. Our territory is extremely vast, and in this vast territory the people have learned the necessary resistance for a long war — to bend the strength of others through their weaknesses. Whoever wants to invade China should remember this truth, and I believe that the Soviets remember it well."
January 1, 1970
https://en.wikiquote.org/wiki/Deng_Xiaoping