The term quagmire might appropriately be applied to the Soviet Union's long years of involvement in the Yemeni civil war. As the conflict dragged on year after year, with little progress made on either side, Moscow felt steadily compelled to increase its commitment to the revolutionary regime in Sana, eventually investing over $500 million of military assistance in an effort to ensure its survival. Yet, after backing the Yemen Arab Republic (YAR) for eight years, even rescuing it from total collapse in 1967–8, by 1970 the USSR was left with few tangible returns to show for its investment. The Soviet Union nevertheless continued to court the YAR assiduously throughout the 1970s.

The tenacity of the Soviet Union's efforts to win influence in Yemen evidently derived from its intense interest in the Arabian peninsula and in the strategic sea-lanes of the Middle East. Impoverished and backward Yemen has virtually no natural resources of interest to a superpower, and its military strength is marginal, but its frontier with Saudi Arabia, its proximity to Ethiopia, and its position on the Strait of Bab el-Mandeb make its geographical location alone a valuable strategic asset. The USSR's involvement in the Yemeni civil war was almost certainly but one facet of a broader effort to win influence in the littoral countries along the Red Sea and the Gulf of Aden: Saudi Arabia, Egypt, Sudan, Ethiopia, Djibouti, Somalia, Yemen, and South Yemen.