Among the several partitioned countries in the contemporary world, Germany, Korea and Vietnam form a d stinctive group which poses particularly intractable problems. For the current divisions in all three arose basically out of the postsurrender occupation zones of 1945 which, although apparently intended to be only of limited duration, subsequently became frozen into immobility during the cold war, so that in all three today a Communist and a non-Communist pair of States, both claiming national legitimacy, face each other across an essentially arbitrary line. During the past twenty years the tensions built up in all three partition zones have threatened to shatter the still precarious peace, but while it would be absurd to sug? gest that this danger is overpast in either Germany or Korea, Vietnam has clearly outclassed both of these in the continuity of the tension it has generated, and it provides what is probably the most menacing flash-point in the world today. It is the purpose of this paper to examine the Vietnamese problem from the standpoint of the political geographer, in the hope of clarifying at least some of the issues involved. The starting point of any such analysis must be the recognition that the Vietnamese problem assumes fundamentally different characteristics according to the basis on which its geographical context is defined. Thus, viewed in its most local context, the situation may appear simply as a civil war between two rival factions both claiming to represent the true ethos of the Vietnamese nation, whereas seen in the continental context of the country's position as the gateway between China and South-east Asia, or in the even wider perspective which relates it to the global distribution of Com? munist and non-Communist Powers, the conflict appears altogether more complex. But, while all of these different contexts are relevant to an understanding of the prob? lem, the critical task is to assess the relative importance to be attached to each. In the thinking of those outside observers who see the problem primarily as an internal conflict, the analogy of the Spanish Civil War seems always to be at least subconsciously present. Hence, it is assumed, the issue is essentially concerned with the challenge presented to an indigenous, leftist Government, in legitimate occupation of the established capital city and commanding majority support in the country as a whole, by a minority right-wing element, dominated by old-style landlords and, until recently, by Catholic politicians, bent on resisting overdue social and economic reforms, and aided in so doing by reactionary foreign Powers. But, quite apart from the extent to which this analogy distorts the ideological differences involved, the internal conflict, as seen by the Vietnamese themselves, is not only an ideological one, but is also deeply rooted in major geographical and historical differences between the north? ern and the southern halves of the country. Unlike the other leading States of mainland South-east Asia, the Vietnamese lands do not centre upon a single great river basin, but comprise two main cores, the deltas of the Song-koi and the Mekong, linked only by an attenuated ribbon of settlement along the narrow and broken coastal zone between the Annamite Chain and the sea. This precarious geographical lay-out has been likened to two bags of rice hanging from a pole, though an equally appropriate analogy today might be with a rattlesnake, in which the noise comes from the southern tail but it is the northern head which determines what happens. Certainly it is the north which represents the primary focus within the country as a whole. It was here, centering in the Song-koi delta, that the original Vietnamese