安史之乱的爆发，破坏了唐王朝内部原有的政治版图和权力格局，藩镇林立的局面开始形成。淮西镇是安史之乱的产物，出于平叛需要，其政区划分打破了“山川形便”原则。区域形势的变化促成了割据，淮西镇在“三吴时期”成为了“河朔割据型”藩镇。从地缘政治视角分析，淮西镇割据局面的形成与其地缘因素息息相关。淮西镇地处中原南部，淮水上游，战略位置紧要，政区西部、南部边界依托桐柏、大别关山要隘，申光蔡三州自成一体，并利用相邻藩镇与中央并不稳固的关系，保持了三十余年较为稳定的割据时期。不过，也正因淮西镇地缘条件所限，战略防御纵深不足，经济基础脆弱，其割据形势也难以长久。

The An-Shi Rebellion shattered the original order of the Tang Dynasty, leaving an empire torn apart by multiple independent provinces. Huaixi was established during this period as the bulwark of the central court against the rebels, for which reason its border was no created according to the local geographical features. Huaixi then turned independent during the reign of “the Three Wu”. Such an independence was made possible by the geographical advantages it possessed. Huaixi was located in the central China and the upper reach of the River Huai, which was of great strategic importance. The fact that its western and southern frontiers were guarded by the Tongbai and Dabie Mountains contributed to its integrity. With these advantages, the governors of Huaixi, utilizing the unstable relationships between the neighboring provinces and the central court, managed to keep its independence for more than 30 years. However, the region lacked strategic depth and was in poor economic condition, because of which the separate state of Huaixi did not last long.