The causes of the Vietnam and Korean wars revolve around the forces supporting communism and those opposed to it. For instance, as of 1954, Vietnam had been divided into a communist northern government under Ho Chi Minh and a democratic southern government under Ngo Dinh Diem. With this division, the northern government sought to spread communism southwards by invading South Vietnam. This drew the attention of the United States, which supported the southern government in stopping the spread of communism (Donaldson 115). On the other hand, the Korean War was caused by the aggression between the communist North and the democratic South along the 38th parallel. The USSR-backed northern government sought to expand communism into South Korea while the US-backed southern government tried to eradicate it, and hence, the obvious tension between the two regions ensued (Donaldson 120).
The engagement of the United States in the two wars brought about mixed results. In the Korean War, the United Nations forces of which the United States army formed the majority force partially succeeded in pushing the enemy forces beyond the battle line. The obvious reason here is that the Korean War started suddenly and the American forces joined the war in large numbers almost immediately. However, in Vietnam, the war started slowly and extended over a period of 10 years. Besides, the United Nations withheld its support for the Vietnam War, meaning that the American forces were left to fight a lost battle. Furthermore, the number of American forces, which were committed into the Vietnam War, grew very slowly (Donaldson 121).
Another important reason as to why the United States failed in the Korean War relates to the differences in which the two wars were fought by the opposing forces. The Korean War was quite conventional and limited considering that there were defined battle zones, the opposing armies came face-to-face, and most age-old tactics were in use. On the other hand, the Vietnam War was dominated by guerrilla tactics. Here, the American forces faced no opposing army and in most cases, the opposing forces used tunnels and civilians to attack. Besides, there were no battle lines such as in the Korean War (Donaldson 125).