World War IV goes by several names. Sometimes it is referred to as the Non-Nuclear World War IV or the Second Vietnam War. However, it is known that the conflict of the war centered on the Peninsula, thus the Second Vietnam War reference. In the end, Imperial America and Japan came out on top, victorious. The United Nations were also involved and it is believed that the Peninsular may be under a new Unified government. Japan, because of their treaty with Imperial America, never became involved in actual combat with the exception of Shunujii.
Evidence also points that military flare-ups occurred in South America and Mexico during this time. Mercenary groups appeared in the hundreds, populated by remnants of armies once connected to nations that no longer exist. The increase in independent states and sovereign regions grew from the chaos that was the last thirty years. The planet remains more divided as ever and several locations exist in the planet where sovereignty falls into question—where no one is really sure who owns or governs what.