The purpose of raising and training an army for a long time is to use it for warfare at a critical time. The significance of this concept has two aspects: one is that for the country, building of the military is a long-term and continuous effort, which should not slacken because it is costly and armed battles are rare; the other is with regard to the officers and soldiers, who should be ready to come forward at critical moments and take up their duties faithfully and bravely. The extended meaning goes beyond the military and refers to long-term preparation or the accumulation of strength in normal times for use at critical moments or whenever necessary.