Balkans
The term is criticized for having a geopolitical rather a geographical meaning and definition, as a multiethnic and political area in the Southeastern part of Europe. The geographical term of a peninsula defines that the water border must be longer than land, with the land side being the shortest in the triangle, but that's not the case with the Balkan Peninsula. Both Eastern and Western water cathetus from Odessa to Cape Matapan (ca. 1230-1350 km) and from Trieste to Cape Matapan (ca. 1270-1285 km) are shorter than land cathetus from Trieste to Odessa (ca. 1330-1365 km). The land has a too wide line connected to the continent to be technically proclaimed as a peninsula - Szczecin (920 km) and Rostock (950 km) at the Baltic Sea are closer to Trieste than Odessa yet it is not considered as another European peninsula. Since the late 19th and early 20th-century literature is not known where is exactly the Northern border between the peninsula and the continent, with an issue, whether the rivers are suitable for its definition. In the studies the Balkans natural borders, especially Northern border, are often avoided to be addressed, considered as a "fastidious problem" by André Blanc in "Geography of the Balkans" (1965), while John Lampe and Marvin Jackman in "Balkan Economic History" (1971) noted that "modern geographers seem agreed in rejecting the old idea of a Balkan Peninsula". Another issue is the name because the Balkan Mountains which are mostly located in Northern Bulgaria are not dominating the region by length and area like the Dinaric Alps. An eventual Balkan peninsula can be considered a territory South of the Balkan Mountains, with a possible name "Greek-Albanian Peninsula", but Greece is rarely defined as a Balkan nation both geographically and in international relations. The term influenced the meaning of Southeast Europe which again is not properly defined by geographical factors yet historical borders of the Balkans.
Balkans
In 1912–1913 the First Balkan War broke out when the nation-states of Bulgaria, Serbia, Greece and Montenegro united in an alliance against the Ottoman Empire. As a result of the war, almost all remaining European territories of the Ottoman Empire were captured and partitioned among the allies. Ensuing events also led to the creation of an independent Albanian state. Bulgaria insisted on its status quo territorial integrity, divided and shared by the Great Powers next to the Russo-Turkish War (1877–78) in other boundaries and on the pre-war Bulgarian-Serbian agreement. Bulgaria was provoked by the backstage deals between its former allies, Serbia and Greece, on the allocation of the spoils at the end of the First Balkan War. At the time, Bulgaria was fighting at the main Thracian Front. Bulgaria marks the beginning of Second Balkan War when it attacked them. The Serbs and the Greeks repulsed single attacks, but when the Greek army invaded Bulgaria together with an unprovoked Romanian intervention in the back, Bulgaria collapsed. The Ottoman Empire used the opportunity to recapture Eastern Thrace, establishing its new western borders that still stand today as part of modern Turkey.