On 18 September 1970 , during the events of Black September in Jordan , Syria tried to intervene on behalf of the Palestinian guerrillas . Hafez al-Assad sent in armored forces equivalent to a brigade , with tanks , some of them allegedly hastily rebranded from the regular Syrian army for the purpose . Other Syrian units were the 5th Infantry Division and Commandos . On 21 September , the Syrian 5th Division broke through the defenses of the Jordanian 40th Armoured Brigade , and pushed it back off the ar-Ramtha crossroads . On 22 September , the Royal Jordanian Air Force began attacking Syrian forces , which were badly battered as a result . The constant airstrikes broke the Syrian force , and on the late afternoon of 22 September the 5th Division began to retreat . The swift Syrian withdrawal was a severe blow to Palestinian guerillas . Jordanian armored forces steadily pounded their headquarters in Amman , and threatened to break them in other regions of the Kingdom as well . Eventually , the Palestinian factions agreed to a cease-fire . King Hussein and Yasser Arafat attended the meeting of the Arab League in Cairo , where the hostilities briefly ended . The Jordanian-Palestinian Civil War shortly resumed , but without Syrian intervention
meeting
1970 Arab League summit
Modern history of Syria