This has a lot to do with historical traditions. Boots are traditional European standard clothes. Germany is a country with a long military tradition, so it is natural to adopt boots. Moreover, boots make the wearer look more upright and energetic, which can enhance the sense of honor of ordinary soldiers. Of course, boots are also very practical. Boots can prevent foreign objects from entering the sole to some extent. The high-waist military boots of the US Army are tied with shoelaces, and then the wading depth can be increased, and the snow area can prevent snow. The Soviet Union inherited the European military tradition of the former Soviet Union, so it also had military boots. China and Japan both followed Germany (Japan also followed France), and the military system and military uniforms were designed with reference to European styles (Japanese military uniforms refer more to France, for example, the epaulettes are vertical, just like France), so they also have boots. The United States was a melting pot of immigrants, without major cultural pillars and weak military strength until World War II. It can be said that everything starts from scratch, so we consider a lot from practicality. Personally, I think American military boots are more suitable for the first-line troops, because of their low cost, no leather, low processing difficulty and very practical. It is also convenient for maintenance and transportation (occupying less space).