Daodejing lunbing yaoyi 道德經論兵要義 "Essential meanings of the discussions on war in the Daodejing", also called Daode zhenjing lunbing yaoyi shu 道德真經論兵要義述 or Daodejing lunbing yaoyi shu 道德經論兵要義述, is a treatise on warfare written during the Tang period 唐 (618-907) by Wang Zhen 王真 (fl. 809), who lived during the reign of Emperor Dezong 唐德宗 (779-804) and occupied the post of court gentleman for consultation (yilang 議郎). Wang was later appointed regional inspector (cishi 刺史) of Hanzhou 漢州 and concurrently commissioner of the military prefecture of Weisheng 威勝軍. In 809, he submitted a memorial to the throne with suggestions for curtailing the power of the military commissioners (jiedushi 節度使) in the provinces.
His 4 juan-long book on military strategy is a military interpretation of the Daoist classic Laozi 老子 (Daodejing 道德經). It stands in contrast to the comprehensive commentaries of Heshang Gong 河上公 (Laozi zhu 老子注, Han period 漢, 206 BCE-220 CE), Yan Zun 嚴遵 (59-24 BCE; Daode zhigui lun 道德指歸論, Han period) and Li Longji 李隆基 (i.e., Emperor Taizong 唐玄宗, r. 712-756; Yuzhu Daode zhenjing 御注道德真經, Tang period). Wang's commentary is not wholly based on the Laozi but also includes Confucian thought and theories of the military writers.
He stresses, for instance, the importance of the virtues of paradigmatic behaviour (de 德), kindheartedness (ren 仁), appropriate conduct (yi 義) and propriety (li 禮). If a person in a high position failed to embody these virtues, it was justified to wage war against him. Warfare was a way (dao 道) of danger, and weaponry was an inauspicious instrument to bring order into the world. On the other hand, civilian rule and martial activity could be seen as two handles (liang bing 兩柄) of which a ruler might make use. Civil rule was master over warfare, and the latter only served as a complement to civilian rule. Yet, in the end, the one could not exist without the other. Negligence of the military would endanger the existence of a state, yet overindulgence in warfare would ruin a dynasty. Warfare was to be an instrument, not a passion.
The literary quality of Wang Zhen's book is rated as relatively good among Tang-period writings. It is included in the Daoist Canon Daozang 道藏, and the series Wanwei biecang 宛委別藏 and Zhihai 指海.