restricted and channeled way in wooded and hilly areas such as New England and Eastern North America and Canada, in West Africa and New Zealand.
Sixth, was the frontier with nucleus communities established, as on the Anglo- Scottish border, on the marks of eastern Germany, or as with the Cossack hordes, or in Southern China, where the community, extended across the frontier into unsettled or disputed territory, often engaged in smuggling and was thus content to be its own defender. This was also characteristic of the American western frontier concept, where, for example, there were mining settlements in Colorado while the Kansas plains were still being raided by Indian tribes. Per- haps, the Russo-Swedish frontier in the 16th and 17th century fell into this cate- gory, as has the Basque country on the Franco-Spanish border.
Seventh, was that rare phenomenon, the mural frontier. The Roman wall across northern England was certainly intended to keep the Picts out or at least act as a barrier against which they could be pinned if they broke in. The wall itself was a highway for defending forces. The English established around Dublin the Pale from which the Irish were excluded. The Roman use of walls is part of the theme upon which Edward Luttwak has expanded, noting that it calls for a perimeter arrangement of defensive forces. But Owen Lattimore has argued persuasively that the Great Wall of China on the Inner Asian frontier was not what it has been depicted - that rather than being designed to keep the nomads out, it was de- signed to keep the Chinese in. It may even have been a public works project whose reason for being changed during or after construction from defensive to constrictive or, in Lattimore's terms, to inclusive.
Eighth, there was the traditional conception of lines between established states, merely marking the political jurisdiction of each government. Nevertheless, the armed and fortified frontier is still with us in various parts of the world, as be- tween North and South Korea and between Israel and neighboring Arab states.
As time and conditions changed, the same area may have become a differ- ent sort of frontier. The sieve became entwined with the nucleus community and then with the mural and finally passed from the military stage to become but an administrative division.
In each of the eight types of frontiers there are differences due to the geog- raphy and to the people on each side. The study of frontiers has to be related to topographical maps or even nautical charts or even, if possible, to visits to see the terrain and the hinterland. Nothing, for example, so explains Israel's attitude to its frontiers as much as a flight over the western Middle East to see the heights, the populated and unpopulated spaces, and the minute size of the area which conditions that nation's response.