Let the invaders enter Central Bulgaria in force, and expose their flanks to Abdul-Kerim in the Quadrilateral, and to Osman Pasha at Widdin; then the Turks, by well-concerted moves against those flanks, would drive the enemy back on the Danube, and perhaps compel a large part of his forces to lay down their arms.

Such is their explanation of the conduct of Abdul-Kerim.
As the Turkish Government is wholly indifferent to the advance of historical knowledge, it is impossible even now to say whether this idea was definitely agreed on as the basis of the plan of campaign.

There are signs that Abdul-Kerim and Osman Pasha adopted it, but whether it was ever approved by the War Council at Constantinople is a different question.

Such a plan obviously implied the possession of great powers of self-control by the Sultan and his advisers, in face of the initial success of the Russians; and unless that self-control was proof against panic, the design could not but break down at the crucial point.

Signs are not wanting that in the suggestions here tentatively offered, we find a key that unlocks the riddle of the Danubian campaign of 1877.
At first Abdul-Kerim in the Quadrilateral, and Osman at Widdin, maintained a strict defensive.