It's all about the Zone Defense

In order to get a better understanding of the area of operations of forces and terrain involved during the Vietnam War it is important to know how South Vietnam was divided militarily.

The Corps Tactical Zone or CTZ
South Vietnam was divided into four zones from north to south based on the military regions organized by the French.

These were:

I Corps – The area south of the Demilitarised Zone (DMZ) to the northern ridges of the Central Highlands

II Corps – The Central Highlands region

III Corps – The populated region between Saigon and the Highlands

IV Corps – The Mekong Delta area

I'll discuss each of these zones in a little more details in further posts.