Another letter came from F---- a month later, this being in answer to one I had rushed off on receiving the card announcing his departure for the Persian Gulf:-- “You ask what we are driving at here, by which I suppose you mean, ‘What is our plan of campaign?’ This, obviously, is a question I can answer only in the most general way. Our principal purpose in the present campaign will be the occupation of southern and central Mesopotamia up to and including the cities of Bagdad and Kerbela, a region roughly corresponding to what might be called ancient Babylonia proper. Our objective in this is twofold. First, to gain control of all the irrigated--and hence highly productive--portion of the Tigro-Euphrates Valley, and, second, to establish ourselves strongly upon the flank of Persia in the event that that country should show a disposition to make common cause with our enemy. [Illustration: MAP OF THE TIGRO-EUPHRATES VALLEY, Where the operations against Bagdad were carried out.] “There is little doubt that the advance to Bagdad will be a fight all the way. The most difficult country will be that between here and about fifty miles north of where the Tigris and Euphrates come together. Most of this area is marshy all the year, and practically all of it will be under water from the spring floods by the time we are ready to get into it. An endless network of ‘canals’ and backwater channels makes it practically impossible to advance on foot even across much of the overflow country, and one of the main reasons for our long halt in Bassorah has been the training of our men in the use of the various native craft which will have to figure in our transport. Luckily, the Turks will be under the same handicap as ourselves in this region, and our superior artillery and organisation are sure to give us the ‘edge.’ The real fighting is going to come when we emerge upon the level alluvial plains of Central Mesopotamia. Here the enemy will have the Bagdad railway at his back, and, without doubt, a pretty complete little system of German-made light railways to keep him in munitions and food. “It may be that it will take us to the end of 1915 to attain our first goal. Then, if a decision in Europe has not been reached in the meantime, our next general advance would be up the Tigris to Samara, Tekrit, and Mosul, and up the Euphrates to Hitt and Deyr; this advance would place in our hands an upland grain-growing region of considerable productivity. Still another campaign would have to be launched to occupy the country up to a line from Aleppo to Mardin or Diarbekir; but Russia should reach this region from the Caucasus before we can get there from the south. Upon the guns and munitions which the Germans are able to send through to Bagdad will depend the character of the stand that the Turk is going to make in Babylonia.