at Basra the Cairo-to-Calcutta line of its great Cape-to-Cairo-to-Calcutta scheme.
The Bagdad Railway, however, did not expose itself to British diplomatic sabotage as France's canal across the Egyptian isthmus had been exposed, for the British Embassy was no longer supreme at Constantinople. It was in Serbia that the German highway to the East crossed the Russian line to the Adriatic, and Austria-Hungary was still seeking a pretext to clear the remnant of the South Slavs from Germany's path. In Serbia lay the frontier of British India. Over the Serbian criss-cross, Great Britain joined Russia in the Anglo-Russian Treaty of 1907, France joined the two of them after the Agadir crisis of 1911 in Morocco, and Europe was divided into two armed camps, a division which pivotted on Serbia.
Meanwhile Great Britain, Russia and France continued negotiations with Germany over the Bagdad Railway. In the Potsdam Agreement of 1911, Russia finally turned down the British scheme for a Trans-Persian line linking the Russian Trans-Caucasian railways with the Nushki Railway from Quetta, and chose to link its Trans-Caucasian system with the Bagdad Railway instead, undertaking to build feeder lines from the Russian zone in north Persia to the main Bagdad line in Mesopotamia. By 1914, Great Britain had withdrawn its objection to the Bagdad Railway and had agreed to support no rival railway, exception being made for a Cairo-Basra line along the Cairo-Calcutta leg of its Cape-to-Cairo-to-Calcutta triangle. At the same time, negotiations were nearing completion between France and Germany, but all these agree-
