战国时期战争频繁,中山国做为春秋战国时期中原北部、河北地区的一个以鲜虞族为主体建立的民族国家,在战国那样一个战乱不断的环境中。为了本国的安全与发展,必然需要建立完善的国防制度和国防体系。1. 关塞要津的防御,春秋时期各国的要塞是不派人进行长期驻守的, 《左传·昭公十三 During the Warring States period, the war was frequent. As a nation-state built in the north of Central Plains during the Spring and Autumn Period and the Warring States Period, Hebei Province was dominated by fresh Yu people. In a war-torn environment like the Warring States Period, For its own security and development, it is necessary to establish a sound national defense system and national defense system. 1. Close the door to Tianjin’s defense, the Spring and Autumn Period fortresses of various countries do not send people stationed for a long time, "Zuo Zhao Gong 13