The changes made in the map of Europe by the Balkan Wars of 1912-1913 were not merely the occasion but a cause and probably the most potent, and certainly the most urgent, of all the causes that led to the World War which raged with such titanic fury from the summer of 1914.
Had the Balkan Allies after their triumph over Turkey not fallen out amongst themselves, had there been no second Balkan War in 1913, had the Turkish provinces wrested from the Porte by the united arms of Bulgaria, Greece, Servia, and Montenegro been divided amongst the victors either by diplomacy or arbitration substantial justice would have been done to all, none of them would have been humiliated, and their moderation and concord would have commended their achievement to the Great Powers who might perhaps have secured the acquiescence of Austria-Hungary in the necessary enlargement of Servia and the expansion of Greece to Saloniki and beyond.
but the outbreak of the second Balkan War nullified all these fair prospects. And Bulgaria, who brought it on, found herself encircled by enemies, including not only all her recent Allies against Turkey, but also Turkey herself, and even Roumania, who had remained a neutral spectator of the first Balkan War. Of course Bulgaria was defeated. And a terrible punishment was inflicted on her. She was stripped of a large part of the territory she had just conquered from Turkey, including her most glorious battle-fields; her original provinces were dismembered; her extension of the Aegean Sea was seriously obstructed, if not practically blocked; and , bitterest and most tragic of all, the redemption of the Bulgarians in Macedonia, which was the principal object and motive of her war against Turkey in 1912, was frustrated and rendered hopeless by Greek and Servian annexations of Macedonian territory extending from the Mesta to the Drin with the great cities of Saloniki, Kavala, and Monastir, which in the patriotic national consciousness had long loomed up as fixed points in the "manifest destiny" of Bulgaria.