I know the basic details around the Yom Kippur War. Egypt and Syria launched a surprise attack on Israel on October 6, 1973. Egypt was able to cross the canal and establish a defensive perimeter 12km deep and use its SAM missiles to establish air cover over its forces.
At the same time Syria launched a massive armored offensive to take the Golan Heights. But somehow Israel was able to stop the Syrian offensive and then with Syria under pressure, Sadat ordered the Egyptians to launch an offensive attack deep into the Sinai which was a total failure.
This weakening of Egyptian Forces allowed the Israelis to cross the canal and encircle the Egyptian 3rd Army.
The lynchpin seems to be the Syrian attack on the Golan Heights. Had the Syrians been successful, the Arabs would have won and would have dictated the terms to Israel.
But can someone explain as to why Syria failed to take the Golan Heights?