The Chavin civilization developed, in part, as a result of the merging of two large rivers--the Mosna and the Huachecsa--in the Mosna Valley, since these provided crucial irrigation for crops.
In 139 B.C.E., the Chinese emperor dispatched Zhang Qian to central Asia to seek allies against the Xiongnu. The Xiongnu were a large confederation of Eurasian nomads who dominated the Asian Steppe.
I'm onI'm only doing this for poems yay sorry for not helping you I do not understand this question or no
It was needed because they needed to fight to win, if they backed off they would get attacked. Therefore, they needed to attack before they did for a better chance of winning.