From what aspects does the poem "Sai Sai Qu" describe the joy of war and chaos?

Li Yi (748-827) was born in Wuwei County, Gansu Province and Dali. He used to be a secretary, a supervisor, a bachelor of Jixian Hall and a minister of rites. I have personally experienced frontier fortress and have written many excellent frontier fortress works. The language is clear and natural, the style is distinct and bold, and the work is excellent. Li Yi's "Song of Xia Sai" depicts the magnificent picture of frontier fortress, and shows the life of frontier fortress soldiers full of lofty sentiments. The title of Xia Sai Qu is mainly used to show the life of frontier soldiers in Tang Dynasty. The whole poem is as follows:

Tribes in Zhou Fan can finish and hunt Yellow River songs at dawn and dusk.

Yan Song is not broken, and the horses are green.

This is a seven-character quatrain, which mainly describes the life and mental state of frontier soldiers. As we all know, the life of soldiers in frontier fortress barracks is hard, just as Liu wrote in "Complaining for the People": "When you are old, the golden river, the jade is restored, and Ma Ce's knife is made in the morning." As for the "resentment" in the "Conscription Book", here, "year after year" means the resentment of conscripts against endless wars, and the word "complex" is also the resentment against the frequent mobilization of frontier fortress; "Korea" is another kind of "resentment" against endless training and preparation. It can be said that every word lists "resentment" and every sentence contains "resentment". Even so, in Li Yi's "Xia Sai Qu", the strong and brave character of soldiers in the Tang Dynasty is more vivid. The first sentence "The tribes in Zhou Fan can end". "Zhou Fan" refers to the northwest frontier. "End" is dressing up. This sentence is a description of the heroic spirit of soldiers, highlighting the soldiers' active and heroic skills in frontier fortress. The second sentence, "Hunting the Yellow River at dusk", is inherited from this sentence and describes hunting in the army. Eating meat is a routine military training. "Yellow River Qu" refers to the Hetao area of the Yellow River. In other words, the border guards practice in the morning and evening, always ready to meet the enemy. These two sentences depict the characters from both static and dynamic aspects, show the mental outlook of the characters from the outside to the mainland, and show the passion and professionalism of the soldiers.