Why did you see Yumenguan in the lonely city, but you didn't break Loulan at once and never return it? Why is Yumenguan in sight, and Loulan is broken before it is returned?

"Looking at Yumen Pass from a lonely city, I will never return the Loulan once" are two poems written by Wang Changling, a poet in the Tang Dynasty. In the poem, "Qinghai has a long cloud and dark snow-capped mountains, and the lonely city looks at Yumenguan" describes the difficult environment in which the soldiers guarding the border are located. The sky above Qinghai Lake is overcast with dark clouds and snowy mountains are bleak, but the lonely city they are guarding is thousands of miles away, and they can only look at Yumen Pass from afar.

The following sentence, "Yellow sand wears golden armor in hundreds of battles, but it won't be returned without breaking Loulan", expresses the tenacity and determination of the soldiers guarding the border. They fought many battles and worn out their armor, but they didn't flinch. As long as there are enemies like Loulan who have not been defeated, they will never return to their hometown.

The "Loulan" here refers to the name of the Western Regions in the Han Dynasty, namely Shanshan State, which is located in the southeast of Shanshan County, Xinjiang Uygur Autonomous Region. During the Western Han Dynasty, King Loulan communicated with Xiongnu and killed the envoys of the Han Dynasty who communicated with the Western Regions many times, so it became the target that the Han army needed to break.