FROM EARLIEST HISTORICAL writings, the nature of warfare is shown to be a struggle for positional advantage at the tactical, operational, and strategic levels. Xenophon writing of the fate of the 10,000 Greeks fighting in Persia in the 4th century Before Common Era, tells of the constant consideration commanders gave to all aspects of the terrain and the disposition of resources as they fought their way homeward. River banks, hilltops, and forests gave advantage to groups of soldiers during tactical combat. Mountains, deserts, and sea coasts gave advantage at the operational level as generals planned campaigns that spanned many miles. Cultural, economic, and political factors, all meshed with the dictates of the physical environment, combined to make up the concerns of military geography. Even earlier (5th century Before Common Era), Thucydides wrote of the consideration of these strategic factors of military geography as Sparta and Athens waged their great Peloponnesian war. It seems as long as mankind has maneuvered for positional advantage in a fight, geography has had military importance. The 2 broad categories of consideration for the military geographer are the physical and the cultural aspects. Political leaders and their military commanders must deal with the realities of the physical and human worlds they strive in. To ignore the salient characteristics of the Earth and the people who live on it will imperil their military-political effectiveness, if not their existence. Relative location and general spatial relationships are of primary concern. Distances dictate modes of transportation, types of weapons, and communications requirements. Sequencing of events and objectives, prioritization of efforts, and assessments of vulnerability will be affected by questions of “how close” and “how big.” The characteristics of the ground topography will determine ease of movement, location of water obstacles, line-of-site for observation and engagement, and general protection from weapons’ effects. The underlying geology and soil types will affect all manner of military engineering works dealing with mobility, fortification, and the effects of weather.