By the summer of 1916, the Roumanians had at last decided that if they wanted to get a slice of Bessarabia from Russia and the province of Transylvania from Hungary, they must jump into the war on the side of the Entente.  It is claimed by some that they had planned to wait until the following winter in order to get their army into the best of condition and training, but that the treacherous prime minister of Russia, Sturmer, when he found that they were determined to make war on Germany and Austria, persuaded them to plunge in at once, knowing that they were unprepared and that their inexperienced troops would be no match for the veterans of the central powers.  At any rate, about the first of September Roumania declared war on Austria and joined the Entente.

The French and English had wished the Roumanians to declare war first on Bulgaria and, attacking that country from the north while General Sarrail attacked it from the south, crush it before help could arrive from Germany, much in the fashion in which poor Serbia had been caught between Austria and Bulgaria a year previously.  The Roumanians, however, were eager to “liberate” their brothers in Transylvania, and so, urged on by bad advice from Russia, they rushed across the mountains to the northwest instead of taking the easier road which led them south to the conquest of Bulgaria. (See maps.)

[Map:  How Roumania was crushed]

Germania, Turkey, and Bulgaria at once declared war on Roumania.  The battle-field in France, owing to continued rains and wet weather, had become one great sea of slimy mud, through which it was impossible to drag the cannon.  General Brusiloff in Galicia had pushed back the Austrians for many miles but a lack of ammunition and the arrival of strong German re-inforcements had prevented his re-capturing Lemberg.  The Russian generals on the north, under the influence of the pro-German prime minister, were doing nothing.  The Italians and Austrians had come to a deadlock.  The country where they were fighting was so mountainous that neither side could advance.  North from Salonika came the slow advance of General Sarrail.  His great problem was to get sufficient shells for his guns and food for his men.  All the time, too, he had to keep a watchful eye on King Constantine, lest the latter launch the Greek army in a treacherous attack on his rear.  For the time being, then, the central powers were free to give their whole attention to Roumania.

Profiting by the mud along the western front and trusting to the Russians to do nothing, they drew off several hundred thousand men from France and Poland and hurled them all together upon the Roumanians.  At the same time, another force composed of Turks, Bulgarians, and some Germans marched north through the Dobrudja to attack Roumania from the south.  Thus, the very trick that the French wished Roumania to work upon Bulgaria was now worked upon her by the central powers.  France and England were helpless.