Beginning in 1945, Yugoslavia's geopolitical situation made it more important than size, economic resources, or military power alone would warrant. Wedged between the Warsaw Pact and North Atlantic Treaty Organization (NATO) alliances in the strategic Mediterranean region, Yugoslavia shared more than half its 3,000-kilometer land border with three Warsaw Pact countries, Hungary, Romania, and Bulgaria, and also bordered two NATO members, Italy and Greece. Neutral Austria to the north and isolationist Albania to the south completed Yugoslavia's borders.
Between 1948 and 1955, the possibility of a Soviet invasion to bring Yugoslavia back into the Soviet orbit remained the largest factor in Yugoslavia's perception of external threat. This scenario involved a possible military intervention in support of pro-Soviet Yugoslavs (see Internal Security , this ch.). Joint Soviet-Yugoslav declarations in 1955 and 1956 prohibited the threat or use of force in relations between the two countries, but the Soviet invasion of Hungary in November 1956 undermined the credibility of those declarations. The Soviet-led Warsaw Pact invasion of Czechoslovakia in 1968 further heightened Yugoslavia's perception of external threat, leading to a dramatic shift in Yugoslav military doctrine (see Military Doctrine , this ch.).
From 1968 until the mid-1980s, many Western and Yugoslav military observers conjectured that if a general conflict erupted between the Warsaw Pact and NATO, the Soviet Union would occupy Yugoslavia. Control of the Yugoslav territory and coastline would split NATO's southern flank and provide the Soviet Navy anchorages and direct access to the Mediterranean Sea. Meanwhile, the Soviet Union also menaced Yugoslavia by supporting with varying degrees of enthusiasm Bulgaria's longstanding claim to territory in the Yugoslav Republic of Macedonia.
Albania also contributed to Yugoslavia's perception of threat during the 1970s and 1980s. Albania had a strong interest in the large ethnic Albanian population in Kosovo, economically the most backward region of Yugoslavia. The explosive conditions in Kosovo caused by unemployment, separatist movements, and Serbian repression created a constant possibility of hostilities between the two countries. Albania could block the Strait of Otranto between itself and Italy, denying Yugoslavia access to the Mediterranean Sea. The combined hostility of Albania and Bulgaria posed a further threat to Yugoslavia. After leaving the Soviet orbit in 1961, Albania preserved its military cooperation agreement with Bulgaria, although it abrogated similar agreements with the other Warsaw Pact countries. Continued relations between Albania and Bulgaria hinged largely on their common hostility toward Yugoslavia.
Meanwhile, Yugoslavia sought to counteract such proximate threats by maintaining good relations with, and obtaining military technology from, other European neutrals such as Austria, Switzerland, and Sweden.
After Mikhail Gorbachev came to power in the Soviet Union in 1985, the perception of Soviet threat to Yugoslavia diminished. Gorbachev's visit to Belgrade in March 1988 apparently allayed many Yugoslav strategic concerns. In a declaration similar to those of 1955 and 1956, the two countries again pledged respect of mutual security.
While in Yugoslavia, Gorbachev addressed the concept of limiting United States and Soviet arms in the Mediterranean region. The Yugoslav reaction to Gorbachev's proposal revealed the influence of the superpower balance in the region on Yugoslavia's perception of its security. Gorbachev's proposal essentially called for the elimination of tactical nuclear weapons from United States forces in Greece and the United States Navy's Sixth Fleet in the Mediterranean. Yugoslavia opposed the proposal because it lacked corresponding reductions in the conventional weapons of the Warsaw Pact and Soviet Union in the region. The diminution of NATO and United States strength would have reduced the relative security of Yugoslavia.
In 1990 rapid political change in Eastern Europe, possible Soviet troop withdrawals, and the declining military relevance of the Warsaw Pact combined to decrease Yugoslavia's perception of external threat. A unilateral Soviet invasion had become a virtual impossibility. Moreover, improved relations between Yugoslavia and Hungary, Romania, and Bulgaria made a coordinated Warsaw Pact invasion unlikely.
Data as of December 1990