most of the civil war was fought in the south but sometimes it was in the north but mostly they were small skimishes
Vietnam shifted the burden of the ground fighting from American troops to South Vietnamese troops during the later stages of the war. This was called "Vietnamization".
Vietnam, North and South Korea. Northern Africa
South
Air war North Vietnam. Ground war South Vietnam.
No, South Korea and the U.S. were on the same side. Both were fighting against North Korea.
North Korea. Also, the American troops spent a lot of time fighting the Chinese since China sent in troops to support North Korea, just as the U.S. sent in troops to support South Korea.
north.
South Korea,Thailand,Australia,New Zealand,maybe more
It was nearly always fighting on home ground; it did not have to do the invading.
During the Korean war the North Korean troops took over almost the whole Korean peninsula. Only due the US led UN troops intervention did the South Korean survive. After Some back and forth fighting with the US + South Korean troops agains North Korean + Chinese troops did the border stabilize where it stands today. US troops remain in South Korea as a deterrant against Norths invasion and to uphold the peace in the peninsula.
One advantage the south had because they were fighting on their own soil was that they could move troops easier. Another advantage was that the south was used to their climate while the north was used to colder temperatures.
Basically, the Vietnamese sides, north and south, each had allies and supporters. These allies joined with the troops in Vietnam. The US was on the side of the south. They lost.