Nelson's history of the war. Vol. XI., The struggle for the Dvina, and the great invasion of Serbia

NEW SITUATION IN THE NEAR EAST. 51

-mense and increasing difficulty. She had south of

her a Bulgarian army watching the Danube, and ‘north the main Austro-German right wing in the Bukovina. If she entered the campaign unsupported she would be in danger of being caught between two fires. The western Bulgarian armies, with von Mackensen’s assistance, would in all likelihood be able to crush Serbia and contain the small Franco-British force to the south ; and though Ivanov was winning successes against von Pflanzer and von Bothmer north of the Dniester, he was still far from making that flank secure. Two conditions seemed essential before Rumania could move. There must be an adequate Allied force on the shores of the North ZEgean to occupy the attention of the main Bulgarian army, and Russia must be able to send sufficient troops to counteract the danger of an Austro-German movement from the Carpathians. Of these two conditions the second was the more important. Rumania was at the moment neutral, with a leaning towards the Allies. But it was clear that in certain events she might be compelled, even against her will, to join the side of the Teutonic League.

There are three routes into Bulgaria from the northern ZEgean. The most westerly runs from Salonika up the valley of the Vardar and down the Upper Morava to Nish, whence the valley of the Nishava takes it eastwards towards Sofia. It is throughout followed by a railway. Farther east the valley of the Struma is open to troops advancing from Kavala. It goes through the heart of difficult mountains, and has no railway and but one road suitable for heavy traffic in winter. The