Bulgaria was the only Warsaw Pact country without a frontier with the Soviet Union. Of the nearly 1,900 kilometers of land borders, 520 were with Romania, 500 with Yugoslavia, 480 with Greece, and 380 with Turkey. With the general exception of Romania, Bulgaria had serious past conflicts with each of these countries. Bulgaria and neighboring NATO members Greece and Turkey had historical disputes that long predated the establishment of their respective rival alliances after World War II. However, unlike its former Warsaw Pact allies in Europe, Bulgaria's traditional enemies were NATO members or nonaligned nations. Relations with Greece had been friendly since 1980, based primarily on a shared antipathy toward Turkey. In 1986 Bulgaria and Greece signed a joint declaration of friendship and cooperation.
The issue of Macedonia was a source of potential conflict between Bulgaria and its neighbors. In 1991 the prospect of civil war in Yugoslavia raised concern that Bulgaria could reclaim Macedonia as a step toward reestablishing the Greater Bulgaria prescribed in the Treaty of San Stefano (see San Stefano, Berlin, and Independence , ch. 1). Bulgaria's Macedonian border had been tense since the Second Balkan War; in 1989 the ouster of Zhivkov escalated the risk that Macedonia would set off political or military conflict with all of Yugoslavia or with its neighboring Republic of Serbia. Bulgarian spokesmen denied having territorial ambitions against Yugoslav Macedonia, but they added ambiguity by referring to it as an open issue. Unlike the Yugoslavs, the Bulgarians did not recognize Macedonians as an ethnic group distinct from Bulgarians.
Proximity to NATO members Greece and Turkey, both with strong armed forces and significant military potential, was Bulgaria's primary strategic concern in the post-Warsaw Pact era. The plan for the development of the BPA was measured against the military programs of those two neighbors. The BPA leadership openly rated both their armies as superior to its own forces, stressing that Turkey boasted military manpower second only to the United States among NATO countries and a population over 100 million. In the view of the Bulgarian military establishment, the size of the Turkish armed forces was the primary standard for determining appropriate reductions in BPA forces, as well as in strategic defense planning. Despite the relative lack of tension in bilateral relations with Turkey and an apparent absence of hostile intentions on its part in 1990, the treatment of ethnic Turks in Bulgaria remained an irritating and potentially explosive issue in bilateral relations. In 1987 veiled threats by Turkey to resolve the issue by force had caused alarm in Bulgaria. The outburst of pro-Turkish and Bulgarian nationalist rhetoric that followed the fall of the BCP regime, which had been willing to suppress ethnic unrest by force, raised ethnic tensions in a period when central government control over society had substantially decreased (see The Turkish Problem , ch. 4).
Even in decline, the Warsaw Pact alliance remained a major factor in Bulgarian threat perception and military planning. Bulgaria continued to count on an ongoing close military relationship and practical cooperation with the Soviet Union to balance perceived security threats. In 1991 the Bulgarian government conducted negotiations for a new bilateral treaty with the Soviet Union to guarantee it against external aggression. In return Bulgaria would pledge not to join any organization, such as NATO, perceived hostile to the Soviet Union. Whatever its relation to the Soviet Union, by 1991 Bulgaria was entering a new, shifting local balance of power similar to the balance that existed in the Balkans before World War II.
Data as of June 1992