As Syria's involvement in the Lebanese civil war following the PLO's guerrilla against Israel was decided, Israel made a decision.
Israel decided to oust the PLO in Lebanon, overpower Syria, set up a massive operation to put Lebanon under their influence, and advance to Beirut, the capital of Lebanon. Israel's ground forces decided to take control of the highway connecting Beirut, the capital of Lebanon, and Damascus, the capital of Syria, through the Bekka Valley, as the possibility of reinforcement of Syria's ground forces through this highway was very high. Syria also needed to defend the highway in order to smoothly move large ground forces to Lebanon, and to do so, it had to be able to effectively prevent the advancing Israeli ground forces. To counter Israel's large-scale armored forces, Syria deployed its armed forces including a huge number of Airborne Assaults in the Bekka Valley, Israel planned airborne bombing attacks to win the war, but Syria knew that Israel was very vulnerable to surface-to-air missiles in the previous Middle East War, so deployed large-scale surface-to-air missile troops to protect Syrian ground forces.