I personally think there are the following points. First, because the two countries are far apart. The main force of Roman army is Roman infantry, and Rome is at war with Carthage, another Mediterranean power. Therefore, Rome did not want and could not wage war against the Han Dynasty. In the Han Dynasty, Dong Zhongshu ousted a hundred schools of thought and respected Confucianism alone. Under the influence of Confucianism, the Han Dynasty would not wage war against Rome, and it was not a threat to itself. Moreover, the wealth accumulated by Emperor Wu of the Han Dynasty in the Xiongnu War for many years had already been exhausted, the population dropped sharply, people's lives were miserable, and the country was in turmoil. Need to rest urgently. Therefore, the Han Dynasty would not wage war against Rome.