Syria played a prominent role in Arab and Islamic history as the capital of the Umayyad dynasty as well as the provincial capital of the Mamluk Empire. Like many other countries in the region, Syria did not gain its independence until the mid 20th century, in 1946. Between 1920 and 1946 Syria was under the French mandate created by the Treaty of Sevres which outlined the disintegration of the Ottoman Empire after the World War I.
After gaining its independence from the French, Syria witnessed a series of coups and counter-coups in 1949 ending with the rule of Colonel Adib Al-Shishakli who ruled until 1954 when he was overthrown in a broad-based coup. During this period Syria also got entangled in Cold War politics as it moved closer to the Soviet block and faced tensions with NATO and its member states, most noticeably with bordering Turkey.
Union With Egypt:
Syria also got drawn into the politics of Arab Nationalism which was a rising force in the late 1950's and into the 1960's, cumulating in the Egyptian-Syrian Union in 1958. Because Gamal Nasser and Egypt assumed a leadership position in the union and did not give equal stature to Syrian officials and considerations, it was dissolved by a bloodless coup in Syria in 1961.
Tensions on the Syrian-Israeli border, including an April 1967 incident when Syria lost several of its fighter jets, led to various antagonistic statements from both sides. Egypt and Syria signed a military alliance in 1966, stipulating that one country would aid the other if involved in war. President Nasser withdrew the UN Emergency Force from the Egyptian-Israeli border and closed the straits of Tiran to Israel, signaling Egypt's readiness to enter into conflict. On June 5, 1967, Israel attacked Egypt and the Six Day War began, which led to Israeli control over the Golan Heights, the Sinai Peninsula, the West Bank.
Syria and Egypt went to war with Israel again in October of 1973 in hopes of regaining lands lost during the 1967 war. Egypt and Syria saw initial success as their forces liberated large stretches of Sinai and the Golan. The second phase of the war saw the United States providing massive support to Israel via an airlift of weapons. The war ended with the acceptance of all parties of the ceasefire mandated by United Nations Security Council Resolution 338.
First Gulf War:
The United States and Syria found common ground when Saddam Hussein's Iraq invaded neighboring Kuwait in August of 1990. Syria was included in the American-led coalition that liberated Kuwait. After the war, Syrian and American officials met in various negotiations with Israel and other Arab countries in hopes of resolving the Golan Heights issue but with no positive result.
Current U.S.-Syrian relations are marred by grievances on both sides. The United States criticizes Syria for interfering in Lebanese politics and playing a negative role in the current Iraq war. Various U.S. executive orders and legislative actions have restricted trade and designated Syria as a sponsor of international terrorism. For its part, Syria has always criticized U.S. policies in the region as one-sided in favor of Israel. And Syrian criticisms of American policies were heightened by the U.S.-led invasion of Iraq in 2003.