There were no longer slaves involved
The answer is Confucianism. Confucius expressed reverence to the parents, elders, and ancestors as VERY important. According to him, the parent to child relationship is the most important one, for a peaceful society depends good filial piety.
USA and Japan were the countries that fought mostly in the south pacific.But you can say Japan bc the US also fought in the European theater whereas japan fought only in the south pacific