On August 1, 1914, the German and Austro-Hungarian empires stood on the brink of the greatest war history had known. Their great need was for alliances that would provide manpower and defense of their borders. In only one direction could these be sought—the Balkan Peninsula. Yet disagreements between foreign officers and high commands increased the difficulty of establishing such alliances. Austrian caution continually clashed with German persistence, for the expansionist drives of the Balkan powers threatened the monarchy's own ambitions. The differences between the two allies were smoothed over in the case of Turkey and Bulgaria, but the ultimate diplomatic failure in Rumania produced much rancor. The author's examination of little known documents in the German and Austrian archives brings to light details of an often tortured relationship. The personalities of those who shaped the course of the war and the playing off of power against power are here clearly revealed.