You will be beaten if you fall behind. Then why don't some poor countries in Africa get beaten?

Obviously, there is something wrong with the sentence 1. 2, there is a problem in understanding. For the first sentence, backwardness is not necessarily beaten, only when others covet you, that is, when they want something from you. Why didn't the United States fight Congo? Because it doesn't make any sense to the second point at all, it can't be simply understood that you will be beaten if you are behind. How can we not fall behind? Developed economically or militarily? Does the Vatican have a developed army? Is there one in New Zealand? It is obvious that he is backward militarily, but he has not been defeated. In fact, it is right for you to understand this sentence as a slogan of hard work. This sentence has a certain historical background. For example, in the late Qing Dynasty, because you had a large population, a large market and abundant resources, others wanted to gain benefits from you. If you refuse to give it to them, you can only solve it by force If you don't use force, you can only be beaten