The people who dwelt on the Babylonian plains, and who made that empire great and populous, sustained themselves by the irrigation of the desert. The same processes of slow destruction which are now so evidently at work over a large portion of our own country, gradually overcame and destroyed the people of Mesopotamia. The floods finally destroyed the irrigation systems. The desert triumphed over man. One of the most densely populated regions of the earth became again a barren wilderness. At the end of the Thirty Years' War Germany was a land wasted and destroyed by war, but war had not destroyed the fertility of the soil. Crops could still be raised in the fields, and trees could be planted on the mountains that would grow into forests. All this was done, and modern Germany rose out of the ruins of the Germany of three hundred years ago. War had destroyed only the surface, leaving the latent fertility of the land to be revived by indomitable human labor. In Mesopotamia it was different. There the forces of Nature destroyed the only means of getting food from the desert. Therefore the desert prevailed and humanity migrated or became extinct. Will anyone question that the defense of Mesopotamia against the desert should have aroused the same intensity of patriotism among her people that has been aroused in past wars for the defense of Germany, or as has been aroused for the defense of Belgium and France and England in the present war? Nature's processes of destruction work slowly but surely. In Mesopotamia they have gone forward to the ultimate end. An entire people who once constituted one of the greatest empires of the world have succumbed to and been annihilated by the Desert. Nature's forces have worked the same complete destruction in many other places in Persia and Asia Minor, and on the eastern shores of the Mediterranean. Northern Africa was once a fertile and populous country. Its wooded hillsides and timbered mountains gave birth to the streams by which it was watered. It is another region of the earth that has been conquered by the destroying forces of nature. The resources of vast areas of that country, its power to sustain mankind, have been finally destroyed by those blighting forces as completely as the city of Carthage was obliterated by the Romans. If the fertility of the lands of Northern Africa had been as indestructible by Nature's forces as the fertility of the lands of Central Europe, a new nation would have arisen in Northern Africa, nursed into being by that indestructible fertility. Wherever the natural resources are destroyed the human race becomes extinct. A battle with an invading army may lead to temporary devastation. A battle with the Desert, if the Desert triumphs, means the perpetual death of the defeated nation. _Which conflict should call for the greatest patriotic effort for national defense?_