Soviet Middle Eastern foreign policy during the Cold War was shaped by two primary concerns, as perceived by the Soviet leadership. The first key priority was ensuring the security interests of the Soviet Union itself, mainly by countering American presence in the region, with the second concern revolving around the ideological struggle between communism and capitalism.[1][additional citation(s) needed] During the Cold War, the USSR first started to maintain a proactive foreign policy in the Middle East as a whole in the mid-1950s. The rise of Arab Nationalism, which was a highly anti-Western movement, enabled the Soviet Union to form alliances with various Arab leaders, a notable example being Gamal Abdel Nasser of Egypt.[2] In order to sustain its sphere of influence in the region, the USSR provided military and economic assistance to pro-Soviet states and exploited regional conflicts and rivalries, such as between Arab states and Israel, to its advantage.[3] The collapse of the Soviet Union in 1991 would result in a power vacuum in the Middle East and contributed to the rise of American hegemony in the region.[4]