Because the Iraqi army, using similar (Russian) equipment and (Russian) doctrine, did so badly against US led Coalition forces in 1991, the PLA (People's Liberation Army; the Chinese armed forces) decided a total restructuring was required for it to be effective in a modern war. Much US terminology was adopted (i.e. corps instead of army). Another change was a separation of administrative and combat lines of authority. The military regions and military districts became more purely administrative and logistic support organizations. A new form of organization called the War Zone Command was created to have operational control of military units in the event of a conflict with a foreign power.
There are seven War Zones, one located and focused on each major potential direction for military conflict. Thus one faces Taiwan, one faces India, one faces Vietnam, and so on. The staff of a war zone plans for operations in its general area and it has a commander who spent much of his career as a senior officer in that area. For example Gen. Liang Guanglie (who leads the Eastern War Zone) was formerly the Commander of the Nanjing Military Region. Before that he commanded a corps and before that he led the elite First Amphibious Mechanized Infantry Division. He was elevated to the Central Military Commission, and resides in Beijing to deliberate with it. But he returns to the War Zone Command Post to conduct major exercises or in the event of war with Taiwan (or an invader). In this respect, the War Zones are similar to the American overseas regional unified commands.
In spite of its regional focus, a War Zone does not have a defined boundary and it does not have specific Military Districts subordinate to it. Instead, an activated War Zone command has general authority over the entire PLA organizational base. The idea is to concentrate most of the offensive (fist) units of the PLA as are useful to insure the War Zone offensive will succeed. According to the US DOD Report to Congress, the peculiar PLA doctrine of active defense means there is little difference between a defensive and an offensive operation: either way the PLA will be on the offensive in the primary front. The object is to keep the fighting away from critical Chinese coastal and urban areas, moving it onto enemy territory or to seaward to the extent possible. PLA planners are told to insure a minimum of 3:1 superiority in any particular battle. Since the War Zone commander is a member of the Central Military Commission, his orders have national weight. He does not need to request anything he just issues orders. Any and every military region must support his orders both operationally and logistically, as required.
This does not mean the entire PLA will operate under the active War Zone Command. Every local military district will retain forces to contain any unexpected threats in their area, mobilizing reserve divisions and brigades if necessary. But it does mean that the PLA will concentrate formidable numbers of third and fourth generation aircraft from the entire nation to achieve either air supremacy, or contested air superiority, in the offensive operational area. In the case of a naval conflict, it also means the oceangoing ships of all three fleets of the PLA Navy will support the activated War Zone Command.. PLA hopes that short duration offensives using the concentration possible under its new command structure, with newly equipped units that have the time to train intensively, will permit it to nibble at its objectives over time even in the cases it does not win dramatically. The War Zone Command with national authority is one of its institutional innovations to that end. -- Sidney Trevethan