Macro-factor that American soldiers can't beat China soldiers: war motive.
Slogans determine why soldiers fight and to what extent they face the war without fear. Slogan rhetoric is a straightforward description of war motives, which is of great significance to the construction of soldiers' emotions.
Regardless of the intention of the leaders who decided to go to war, we can see that China's core mobilization rhetoric is "Resisting US aggression and aiding Korea and defending the country". Protecting one's family is the most powerful and common selfish motive. Once soldiers believe this, their will to fight will become stronger.
Individual factors: peer expectation
We know that we can use the reward and punishment system to make the army rampage. But in any case, from any standard, the most reasonable self-interest behavior of a soldier who is about to die or be injured is to avoid the cold. John Key Gump, a military historian, believes that "every army is made up of a group of soldiers who desperately want to escape". A soldier who escapes may be tried by a military court or directly punished (such as shooting deserters), but what if a group of soldiers want to escape collectively? No one arrested them, and their escape was much better than the pain and death they faced.
The iron law of modern warfare is that interventionism will fail.
In fact, after World War II, major wars with international influence in the second half of the 20th century, except the Middle East war, were almost all some form of interventionist wars, and except the Soviet Union's occupation of Afghanistan, these interventionist wars were almost all initiated by the United States.
All these modern interventionist wars called civilization and altruism, such as Vietnam War, Korea War, Gulf War, Somalia War, Iraq War and Afghanistan War ... are almost all based on altruism and the rapid end of the war as the main reason for war mobilization.
Why can't Americans win the Korean War? We all know that this war is a rare unsuccessful war in the history of American war, and the US military is advanced in equipment. There are fighters, tanks, the most advanced rifles, sufficient quantity and strong logistics support ability. Looking back at China, it is no exaggeration to say that there is nothing I want. The Korean War should be a proxy war between the United States and the Soviet Union, but the Soviet Union did not directly send troops to the war. Without the powerful comrade-in-arms of the Soviet Union, our strength would be worse than that of the United States. However, when the two armies meet, the brave wins. Our volunteers are not afraid of bloodshed or sacrifice. They would rather use their chests to resist gunfire for their comrades. Our army takes advantage of terrain and other advantages to try to avoid American artillery attacks. That courage and bravery are the best in the world.
But the US military is completely different. Surrender if you can save your life. In the complex battlefield, they will be timid and passive as long as they see our fierce offensive. Coupled with the failure to gain the initiative in ground operations against our army for many times, the morale of the US military is insufficient, and even war-weariness has arisen. How can it be an opponent who commands the volunteers?
Moreover, the main interests of the United States are concentrated in Western Europe. Even if it loses control of the Korean peninsula, the United States can still proceed from Japan and continue to deploy its forces in the Far East. So the Korean peninsula is not very important to the United States. Seeing that the bones of our army were too hard to chew, the United States began to calculate the gains and losses of this war and found that it had invested too much equipment and troops in the war. Therefore, the United States seeks a truce and stops losses in time.