These depredations reflect to a great degree the complementary relation of highlands and lowlands. The plains possess what the mountains lack. This is a fundamental fact of economic geography, and inevitably leads to historical results. The marauding expeditions of mountain peoples first acquire historical importance, either when the raids after long continuance end in the conquest of the lowlands, and thus augment the resources and population of the highland state; or, as is often the case, the raiders call down upon themselves the vengeance of the plainsmen, are subdued, and embodied in the lowland state. The conquest of ancient Assyria and the destruction of Nineveh by the mountain Medes seems to have been a process of this kind. Long before their descent upon Mesopotamia, they were known as the "dangerous Medes," were constantly threatening the Assyrian frontiers and occupying isolated tracts.[1372] The predatory incursions of the Samnites of the Apennines into the fertile fields of Campania eventuated in the conquest of ancient Capua and other cities, and greatly strengthened the Samnite Confederacy. But this encroachment of the mountain tribes upon the plains aroused the cupidity and alarm of the Romans, who in turn bent their energies toward the final subjugation of the Samnites.[1373] Himalayan Nepal, after the unification of its petty Rajah states by the Gurkha conquest between 1768 and 1790, began encroachments and ravages upon the Indian Terai or fertile alluvial lowland at the foot of the mountains; and finally by 1858 had acquired title to a considerable strip of it, which by its rice fields and forests greatly strengthened the geographic and economic base of the highland state.[1374] The Malay Hovas, inhabiting the central plateau of Madagascar, braced to effort by its temperate climate and not over-generous soil, have almost everywhere subdued the better fed but sluggish lowlanders of the coast.[1375] There can be little doubt that the beneficent effects of an invigorating mountain climate, especially in tropical and subtropical latitudes, have helped the hardy, active hill people to make easy conquest of the enervated plainsmen.
Conquest of mountain regions
It is more often the case, however, that the scant resources, small number, and divided political condition of the mountain tribes make such conquest impossible. Their depredations provoke reprisals from the stronger states of the plain, who bring the mountain region under subjection, merely to police their frontier. Strabo makes it clear that the Romans, having secured certain passes over the Alps, neglected the conquest of the ranges, till the increase of Roman colonies along the piedmont rim excited the cupidity of the mountaineers. Muscovite dominion was extended over the Caucasus, both in order to check the persistent raids of its tribes into the Russian plains, and to secure control of its passes. The state of Kashmir, guided by a purely local policy, for years tried to conquer the robber tribes on its northwestern frontier, merely to protect its own border provinces. Then the British authorities of the Indian Empire began the same process, but from a radically different motive. They saw the Gilgit and Hunza valleys, like the Chitral to the west, as highways through a mountain transit land, whose opposite approaches were held by the Russians.[1376]
Such conquests, whatever be their motive, profit the vanquished in the end more than the victor. They result in the systematic and intelligent development of the mountain resources, and the maintenance of ampler social and economic relations between highland and lowland through the construction of roads, which must always represent the reach of the governing authority. The conquest of mountain peoples means always expensive and protracted campaigns. The invader has always two enemies to fight, Nature and the armed foe. There is a saying in India that "In Gilgit a small army is annihilated and a large army starves to death." Hunger is king in high altitudes, and comes always to the defense of mountain independence. Moreover, the inaccessibility of such districts, the difficulty of maintaining lines of communication, ignorance of by-paths and trails which forever offer strategic opportunities to the natives or escape at a crisis, all serve to protract the war. The independent spirit of the mountaineer, his endurance of hardships, his mastery of mountain tactics, and his obstinate resistance after repeated defeat, give always a touch of heroism to highland warfare. Consequently, history abounds in examples of unconquered mountain peoples, or of long sustained resistance, like that which for sixty years under the heroic leadership of Kadi Mulah and Shamyl used up the treasure and troops of Russia in the impregnable defiles of the Caucasus. In the end, however, the highland tribes succumb to numbers and the road-making engineer.
Political dismemberment of mountain peoples.
Political dismemberment, lack of cohesion due to the presence of physical barriers impeding intercourse, is the inherent weakness of mountain peoples. Political consolidation is never voluntary. It is always forced upon them from without, either by foreign conquest or by the constant menace of such conquest, which compels the mountain clans to combine for common defense of their freedom. The combination thus made is reluctant, loose, easily broken, generally short-lived. It becomes close and permanent only under a constant pressure from without, and then assumes a form allowing to the constituent parts the greatest possible measure of independence. The Swiss canton and commune are the result of a segregating environment; the Swiss Republic is the result of threatened encroachments by the surrounding states. It owed its first genuine federal constitution to Napoleon.
A report on the situation in the Caucasus, addressed to Czar Nicholas in 1829, contains an epitome of the history of mountain peoples. It runs as follows: "The Circassians bar out Russia from the south, and may at their pleasure open or close the passage to the nations of Asia. At present their intestine dissensions, fostered by Russia, hinder them from uniting under one leader; but it must not be forgotten that, according to traditions religiously preserved among them, the sway of their ancestors extended as far as to the Black Sea. * * * The imagination is appalled at the consequence which their union under one leader might have for Russia, which has no other bulwark against their ravages than a military line, too extensive to be very strong."[1377] Here we have the whole story—a mountain people pillaging the lowlands, exercising a dangerous and embarrassing control over the passes, and thereby calling down upon themselves conquest from without; weakened by a contracting territory within the highlands and a shrinking area of plunder without, doomed to eventual defeat by the yet more ominous weakness of political dismemberment.