But this much being decided, there remained the question how, exactly, the blow was to be struck. Was the British force in Mesopotamia to be destroyed as a preliminary to a further advance into Persia, or were the two operations to be attempted at the same time, or could the British in Mesopotamia be left alone for the moment and an advance into Persia, into their rear, be made without attacking them directly? From the great city of Baghdad, the capital of Turkish Arabia, and the immediate base for operations on the central front, it was possible to avoid the Mesopotamian route, and to strike at Persia by a more northerly line. Which of the three schemes was the best to adopt? The question seems to have been considered in detail. Eventually it was decided that the third was the most promising. The argument which prevailed with the Turks or their German advisers seems to have been that the British army in Mesopotamia, though lately worsted in its onslaught on prepared positions, was a formidable enemy to attack in the field, and one moreover who was being reinforced from England and India. Such an attack would be a very serious and at best a lengthy operation. It would be better to avoid a direct attack, to make such threats and demonstrations in Mesopotamia as would suffice to keep the British in apprehension of a Turkish offensive, and to leave them facing the positions from which they had suffered so many repulses at the beginning of the year. They would probably be careful about assaulting those positions again, and if in the meantime a Turkish force were to invade Persia, they would probably have to expend their strength in meeting it there. A considerable number of troops was therefore prepared for an advance on the Persian frontier by northerly routes, while the Turks in Mesopotamia were reinforced to such an extent only as seemed sufficient for the maintenance of their main positions on the Tigris, and for threatening demonstrations on the Euphrates.