论武帝以前的汉匈关系

武帝以前高祖、惠帝和高后时期，由于国势不振，汉朝试图通过和亲来“约束”匈奴侵扰。但是，匈奴一再背约的现实，迫使汉朝统治者对以往单纯依靠和亲以消弭匈奴入寇的政策进行反思和调整。文景之世，在继续与匈奴和亲的同时，还采取了向西北边地移民和入粟于边以拜爵、除罪，建立官营牧马苑和鼓励民间养马等积极防御措施，使汉朝在西、北边塞的被动局面有所改变，从而为汉武帝武力反击匈奴创造了条件。

The Paper on the Relationship Between Han Dynasty and Xiongnu Before Han Wu Emperor

The relationship between Han and Xiongnu before Wu Emperor was kept peace mainly by adopting the policy of "Political marriage". During the periods of Gao, Hui emperors and the period of Gao queen, they tried to restrain Xiongnu from invasion with political marriage, because the military and economy were not that powerful. The fact that Xiongnu betrayed and didn't stand by the negotiation they had made with each other forced Han dynasty to rethink over and reform the Policy that they had only used the simple way of political marriage to defend Xiongnu's invasion .During the periods of Wen and Jing emperors, besides insisting on the policy of "Political marriage" with Xiongnu ,they also took some other positive measures, such as migrating some people to the frontier, entitling the people giving the corps to the frontier with titles ,sin relief, starting the national horse keeping and encouraging the people to keep horses, etc, in order to have the passive position of Han dynasty in west and north frontier changed, which helped Han Wu emperor create lots of conditions to defend and attack Xiongnu with armed forces. Therefore, either the policy of "Political marriage" and "gradual titling", or the policy of attacking with armed forces, was based on the contrast between the two sides, the Han dynasty and Xiongnu.