The parallelism in this couplet is extremely clever.
Tips
history
A core aesthetic of classical Chinese poetry from the Six Dynasties onward. In a 七律 or 五律, lines 3-4 and 5-6 must be 对仗: nouns pair with nouns, verbs with verbs, tones alternate level/oblique (平仄), and concepts mirror or contrast.
usage
工整 (neat, well-formed) is the standard praise for good 对仗. The noun form usually just means 'parallelism'; the verb use 'to wage war' (CC-CEDICT) is archaic and rare in modern speech.