Bulgaria has had nearly a century of modern independence, during which its borders have invariably been imposed upon it by others. This has been the case partly because the Balkan Peninsula was for many years a pawn in the balance-of-power politics of the more powerful European nations and also because Bulgaria has been on the losing side in three of its four major wars. It even fared badly at the peace table after the only war in which it emerged victorious (see ch. 2).

In spite of these circumstances, the country has boundaries that have many natural physical characteristics and that have imposed no serious economic hardship on any significant group of people. They also contain a large percentage of the Bulgarian people, although numerous population resettlement movements have contributed to this end. None of its borders are officially disputed.

The total boundary of Bulgaria is about 1,415 miles long. Rivers account for about 425 miles of it, the Black Sea coast for 248 miles, and a great portion of the remainder adheres to ridges in high terrain.

The western and northern boundaries are shared with Yugoslavia and Romania, respectively, and the Black Sea coastline constitutes the entire eastern border. The southern boundary is shared with Greece and Turkey.

Nationalists have territorial ambitions stemming from the size of the Middle Ages Bulgarian empire that encompassed about one-half of the Balkan Peninsula but, in the local political climate that has existed since World War II, such ambitions are not seriously considered.

The post-World War I boundaries were established in rough detail by the Treaty of Peace between the Allied and associated powers and Bulgaria, signed in 1919 at Neuilly-sur-Seine. They were demarcated by international commissions between 1919 and 1922, formalized by the Treaty of Lausanne in 1923, and reconfirmed by the Treaty of Paris in 1947.

During World War II, again as an ally of Germany, Bulgaria briefly reacquired the coveted portions of Macedonia and Thrace, but the interwar boundaries were restored without much deliberation in 1947 with the agreement of the Soviet Union as well as all of the other major victorious allies. Small deviations from the borders established in the early 1920s have been made for local reasons, but none of them have been of national significance.

The 335-mile border with Yugoslavia was drawn in an attempt to follow the high ridges separating the watersheds of the Morava and Vardar river valleys in Yugoslavia from those of the Iskur and Struma valleys in Bulgaria. The border starts in the north at the junction of the Timok River and the Danube, but it follows the river for only about ten miles. Leaving the Timok (with a few exceptions when it must cross river valleys), it remains on high ground until it reaches the tripoint with Greece. Although nationalist Bulgarians continue to feel that Bulgaria's share of Macedonia—which it shares with both Yugoslavia and Greece—is less than just, there are no overt official disputes of the boundary.

The border with Greece is 307 miles long—all but forty-nine miles of which are overland. The major portion of it follows higher elevations and ridges in the Rodopi. East of the Struma and Mesta river valleys, insofar as it is feasible, the border is at the dividing line between the Maritsa River basin and those of the streams that flow southward to the Aegean Sea.

Following an official visit by the Greek foreign minister to Sofia in 1946, the Bulgarian premier stated that "all territorial claims [between Greece and Bulgaria] are excluded forever." This statement indicates that boundary frictions that had persisted for many years were officially eliminated at that time, and as of 1973 the border was not disputed.