Well if you are not knowledgeable in that matter, better ask someone, not the biased media. I'll try to be short in the explanation.
Think that in 1975, Henry Kissinger was in love with the personnality of Assad. It was a trend with that distorded mind to give away something he does not own to someone everybody hates. Lebanon was an example, at the same time East Timor was another one.
Syria has a long history in thinking that Lebanon is its backyard and that it is an ownership. In 1958, it took a president like Eisenhower to land the Marines in Lebanon at a time King Faysal of Irak was toppled by pan-arab units in the army, at the same time arms were flowing in Lebanon from Syria to arm the insurgency.
Starting 1965, Syria sent thousands of irregular palestinians to promote chaos in Lebanon. It peaked in 1973. In 1975, it was an open interference in Lebanese affairs, political and military. A pure blackmail operation, imposing political will in exchange of some short cease-fires. Take and ask for more, until it culminated on Oct. 13, 1990. Then George Bush gave the green light for the Syrians to take control of all Lebanon using their aviation, in exchange of the syrian cooperation in the Gulf War.
Syria played the pyromanical fireman since 1975.
Destro you are distorting History.
Great post.