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Response by Governments
In 2090, there was a small-scale battle fought in secret. Only a small amount of troops was used. One of the likely reasons for this is that the leaderships of both the U.S. and Soviets feared another great war. Thus, the two great powers kept the conflict hidden. 
Tanks, fighters, and warships weren't used in the secret battle. Rather, it was a battle between small magician units who clashed over and over again. 
The grueling war inflicted a great blow to the strength of magicians in both the USNA and New Soviet Union. The USNA lost William Sirius and other Star Class combat magicians who died in battle. The loss of strength in magicians in the Far East of the New Soviet Union was catastrophic, and thus their military presence declined significantly over several years. When the threat of the New Soviet Union in the north began fading away, it led to the Great Asian Union gaining motivation to invade Okinawa, which resulted in the Okinawa Defense Navel Battle.