朝鲜战争是我们的立国之战，洗刷了近百年的屈辱史，在美版知乎Quora上，美国网友提问道：为什么中国在20世纪40年代那么弱，之至于无法抵抗日本的入侵，却在20世纪50年代突然能够将美国领导的联合国部队赶回三八线？在这么短的时间内发生了什么变化？这引起了各国网友的围观和热议，我们看看他们的观点。
问题
美国华裔网友马里奥李的回答
In fact, the answer is already in your question.
事实上，答案已经在你的问题中了。
Your question: Why was China so weak in the 1940s that it could not resist the Japanese invasion, but in the 1950s it was able to repel the United Nations forces led by the United States back to the 38th Front? What has changed in such a short time? It is mainly because they have changed from a loose sand to a people&39;s concerns.
突然间，中国面临着来自朝鲜方向的又一次可能的入侵（日本帝国首先征服了朝鲜，并从那里开始了对中国的入侵）。美国飞机偶尔侵犯领空、随机轰炸逃离的朝鲜军队，以及麦克阿瑟将军威胁轰炸中国沿海城市，妄称帮助国民党当局夺回中国大陆，证实了中国人的担忧。
Hiroshima was only five years away. The good image of Americans among the Chinese (American mercenary pilots flying for China, also known as Flying Tigers, are rock stars) was immediately replaced by new memories of atrocities committed by foreign powers after their occupation. The Chinese people are determined to protect their hard won freedom. Even Chairman Mao sent his eldest son to fight in Korea (later died in the US bombing).