The difference is due to geographical conditions. Except in a small area Assyria was not suited for agriculture, and there could be' no great extension of that area. In Babylonia the land is flat and little above the level of the streams, so that canals for irrigation and commerce could easily be constructed, but in Assyria the rivers for the most part lie just too far below the level of the land to be of much service. The district suited for irrigation and agriculture enjoyed a fertility which passed into a proverb, but it was too small to support a large population. Nor had it more protec tion than was afforded by the surrounding steppe, which becomes dry enough to be called desert only on the south-west. Its peoples, if they are to be defended, must defend themselves. Though probably not Baby lonians themselves, they brought from Babylon a civilization in advance of the times, and were able to defend themselves successfully against their enemies. For defence, a strong centralized government is an advantage, so from the beginning Assyria, ruled from Nineveh, was a single monarchy, a state which grew by conquering the surrounding tribes less advanced in arts of war. By 1400 B.C. it was able to give up the farce of allegiance to Babylon, and was even able to invade Babylonia.
Fighting was bred into the Assyrians. The lesson they had learned under the stimulus of geographical conditions was that they must take energy from others, as there was not enough available to serve their needs. Babylonia, the mountains on the east, Syria, Palestine and Phoenicia were all laid under tribute. But for long they evolved no system of government to make the most of captured provinces. All the neighbouring states were overrun when they rebelled against the power of Assyria, but they were left to themselves while they paid tribute, or in times when the central authority was weak. It was only as late as 750 B.C., under what is called the Second Assyrian Empire, that any attempt was made to consolidate conquests and use the subject states to the best advantage, so that the whole trade of the Eastern world might be controlled.
This was a somewhat higher ideal of government, but the attempt to found a trading empire by cruel conquest was as unsuccessful as the attempt to continue a trading empire without being prepared to defend it. First one tributary state and then another revolted. Some revolts were put down, but wherever Assyrian armies were not, there rebellion broke out afresh. Ringed round by races united in their hatred of a conqueror if in nothing else, Assyria was attacked and utterly destroyed.
Babylonia, having at length learned something of the value of united action, for a short time raised an empire on the ruins of Assyria, under a dynasty founded by a former viceroy ; but on the heights of the Median plateau a new danger threatened. Brought into contact
with the outer world by the trading schemes of Assyria, the Medes beyond the border mountains learned of the lowlands, and at length descended to the plain and made it all their own.
In all this history the geographical control is evident, but the history is not so simple as that of Egypt, because the geographical conditions are more complex. The main facts are, however, obvious. At first Babylonia had the opportunity to evolve a civilization of its own because to climatic conditions, at once providing suffi cient energy and reacting on the minds of men towards a saving of energy, there was added adequate protection. Then Assyria took the lead because the geographical conditions stimulated her peoples to protect themselves. Just as long-continued exposure to protected conditions evolved races in Egypt and Babylonia almost incapable of protecting themselves, so continued exposure to con ditions requiring self-defence reacted in producing races in whom fighting for its own sake was an essential of life.
Since Nineveh fell, the geographical conditions have continued to act, for Assyria having failed to set up an empire based on force, the whole lowland of the Tigris and Euphrates has been a unit of which the most im portant part has been Babylonia. But, as in Egypt, the lesson taught by thousands of years was difficult to unlearn. The tendency of things .to continue as they have been, is tremendously strong, and Babylonia has never been independent. To Elamites, Kassites and Assyrians succeeded Medes, Persians, Greeks, Romans, Arabs and Turks, so that, after 3000 years in which its original defences have counted for nothing to men who have reached a higher standard of living, and in which it has lain open to whatever people chose to take it and make what they could for the time, there is no wonder that Babylonia is now little more than its original swamp.
Yet the land is able as of old to produce its fruits and on a greater scale than in the past ; vast reservoirs, as in Egypt, may hold up water from times of plenty for times of scarcity, and more effective provision may be made for the diversion of the floods which, uncontrolled, cause these swamps. Under wise rule it might again be a garden.
has been pointgd out that two centres of civilization arose in Egypt and Mesopotamia because the geographi cal conditions in these two regions gave the people living in them an advantage, on the whole, over their fellows elsewhere. The rise of these two centres, and especially of the latter, affected the inhabitants of other districts near them. Naturally those peoples inhabiting the lands between the two were affected not, perhaps, as greatly as others at any one time, but more continually and in the long run more effectively.