近年来，区域历史地理研究成果斐然，区域历史军事地理作为其研究方向之一亦颇受关注。它是以历史上特定的区域为研究对象，对该区域内所发生的军事现象进行分析，从而找出地理条件对军事行动，乃至对敌对双方对峙格局、生死存亡的影响。已故著名史学大师史念海先生的《河山集》（第四集），开启了中国现代意义上的历史军事地理研究的先河，宋杰先生的《中国古代战争的地理枢纽》，可谓这一领域的一部精品之作。

在中国古代历史上，河西是一个重要而独特的地理单元，它“东连关陇，西通西域，南接种羌（后为吐谷浑、吐蕃），北达匈奴（后为突厥），恰似中原王朝的一支手臂，汉代就被称为‘天下要冲，国家藩卫’”。秦陇、河西、西域三者密不可分，能否控制和经营好河西，不仅直接左右着秦陇和西域的安危，也是衡量历代中原王朝政权兴衰的风向标。因而许多影响中国历史进程的重大事件都与这里紧密相关，如张骞通西域、汉匈河西之战、汉设河西四郡、唐张议潮收复河西、西夏建置西凉府、明修长城等。河西既是各民族和谐共处、交会融合的美好家园，也是各民族反复争夺的重要战场。

河西自汉武帝元狩二年（前121）归汉以来，终两汉之世，一直是汉朝重点经营的战略区域。河西四郡的设置，不仅起到了隔绝匈羌、拱卫秦陇，沟通西域的重要作用，而且成为汉朝西征西域、北伐匈奴的军事基地，引导了汉匈战争的最终走向，其军事战略地位远非其他区域所能比拟。目前关于河西的专题研究，主要集中在政治、经济、交通、文化等方面，研究成果也非常丰硕，为研究和开发河西提供了一定的借鉴。但从军事地理角度关注者甚少，仅在军事史和为数不多的学术论文中有所涉及，但也往往侧重于综述或介绍境内所发生过的某场战争而已，未有从战略层面全面审视河西军事战略地位的研究。毋庸置疑，汉代的河西首先是一个军事战略区域，所以该角度的研究不可或缺。

汉代河西的军事战略价值，与其所处的地理位置具有重要的关联性，相关的地理条件如高山、大河、险关、要隘以及地缘关系等，对军事行动或整个国家以及更广大的地区，又有怎样的作用和影响，也是值得深入思考和研究的问题。值得注意的是，除地理因素外，国力的强弱、将帅的谋略、敌对势力的政治稳定与否等，对河西的军事战略价值也有着直接或间接的影响，是多种因素综合作用的结果。

《汉代河西经略史》一书是在我的博士毕业论文的基础上补充修改完成的。该书选取两汉时期的河西作为研究对象，深入探讨该地区的经济环境、地理特点对汉匈百年战争的影响进行深入地分析与探讨。与此同时，引入现代军事地理学的有关理论，从国家战略层面审视河西的战略地位及其作用，并从中总结出其价值演变规律。因本人学识浅薄，水平有限，书中错误和疏漏在所难免，恳请各位专家学者批评指正。

2017年4月

In recent years, the research results of regional historical geography have been remarkable, and regional historical military geography has also attracted much attention as one of its research directions. It is to take a specific area in history as the research object, analyze the military phenomena that occur in the region, and find out the impact of geographical conditions on military operations and even on the confrontation pattern and survival of the opposing sides. The late famous historian Mr. Shi Nianhai's "Collection of Rivers and Mountains" (the fourth episode) opened a precedent for the study of historical and military geography in the modern sense of China, and Mr. Song Jie's "The Geographical Hub of Ancient Chinese War" can be described as a masterpiece in this field. In ancient Chinese history, Hexi was an important and unique geographical unit, which "connected Guanlong in the east, the western regions in the west, the Qiang (later Tuyuhun and Tubo) in the south, and the Xiongnu (later Turkic) in the north, just like an arm of the Central Plains Dynasty, and the Han Dynasty was called 'the world to rush, the state guard'". Qinlong, Hexi, and the Western Regions are inseparable, and whether Hexi can be controlled and operated well not only directly affects the security of Qinlong and the Western Regions, but also is a weather vane to measure the rise and fall of the Central Plains dynasty regimes in successive dynasties. Therefore, many major events that affected the course of Chinese history are closely related here, such as Zhang Qiantong's Western Regions, the Battle of Han-Hun Hexi, the establishment of the four counties of Hexi by the Han Dynasty, the recapture of Hexi by Tang and Zhang Yichao, the construction of Western Liangfu in Western Xia, and the Great Wall of Ming Xiu. Hexi is not only a beautiful home for harmonious coexistence, convergence and integration of all ethnic groups, but also an important battlefield for repeated competition among all ethnic groups. Since the return of Emperor Wudi of the Han Dynasty to the Han Dynasty in the second year (121 BC), Hexi has been a strategic area focused on the operation of the Han Dynasty. The setting of the four counties of Hexi not only played an important role in isolating the Huns and Qiang, guarding Qinlong, and communicating with the Western Regions, but also became the military base of the Han Dynasty's western expedition to the Western Regions and the Northern Expedition against the Xiongnu, guiding the final direction of the Han-Hungarian War, and its military strategic position was far from comparable to other regions. At present, the special research on Hexi mainly focuses on politics, economy, transportation, culture and other aspects, and the research results are also very fruitful, which provides a certain reference for the research and development of Hexi. However, from the perspective of military geography, little attention has been paid to it, only in military history and a few academic papers, but it also tends to focus on reviewing or introducing a war that has occurred in the territory, and does not comprehensively examine the military strategic position of Hexi from the strategic level. Undoubtedly, Hexi in the Han Dynasty was first and foremost a military-strategic region, so the study of this perspective is indispensable. The military strategic value of Hexi in the Han Dynasty has an important correlation with its geographical location, and the relevant geographical conditions, such as high mountains, large rivers, dangerous passes, key points and geographical relations, and how they have a role and impact on military operations or the entire country and the wider region, are also issues worthy of in-depth consideration and study. It is worth noting that in addition to geographical factors, the strength of national strength, the strategy of generals, and the political stability of hostile forces also have a direct or indirect impact on Hexi's military strategic value, which is the result of the combined effect of many factors. The book "A Brief History of the Hexi Classics of the Han Dynasty" was supplemented and revised on the basis of my doctoral dissertation. The book selects Hexi in the Two Han Dynasty as the research object, and deeply analyzes and discusses the impact of the economic environment and geographical characteristics of the region on the Han-Hungarian Hundred Years' War. At the same time, the relevant theories of modern military geography are introduced to examine the strategic position and role of Hexi from the national strategic level, and the law of its value evolution is summarized from it. Due to my shallow knowledge and limited level, errors and omissions in the book are inevitable, and I sincerely ask all experts and scholars to criticize and correct. April 2017（AI翻译）