At that time, emir Rukn Ad-Deen Baybars shook violently, and he had a strong passion for religion, great enthusiasm for putting an end to the Tatars, and a sweeping desire to fight. But he found himself only one among a group of slack betrayers. Emir Rukn Ad-Deen Baybars cried at the face of Zayn Ad-Deen Al-Haafithi, and abused him harshly, and even could not help striking him. He said to him: "It is you who would lead the Muslims to destruction."

Of course, it was An-Naasir Yoosuf himself whom Baybars intended; he was among the most important means that led the Muslims to destruction. But the Baybars seemed to address a group of the dead, and in no way could the dead hear! No one was impressed by his words: {Indeed, you will not make the dead hear, nor will you make the deaf hear the call when they have turned their backs retreating.} [Quran 28:80] And they were indeed dead, deaf and retreating.
They then took the suitable decision, in their view.
The decision was to flee!
Emir An-Naasir Yoosuf, along with the other emirs and army soldiers would run away, leaving the large city of Damascus and its great population unprotected; we all belong to Allaah, and to Him we all shall return.

Finding no solution with those, Rukn Ad-Deen Baybars moved to Gaza of Palestine therefrom he communicated with Sultan Qutuz of Egypt, asking for return, in the hope of unifying efforts to face the Tatars. The sultan of Egypt received him warmly; and we shall talk about this in detail later, Allaah willing.

Damascus became void of emirs and guards. Being a big and impregnable city, Damascus was expected to keep firm for a long time before its fall. However, it was the habit of such emirs as An-Naasir Yoosuf to enjoin and encourage resistance as long as war was far from their land. But once the armies of the enemies came close to their territories, flight would always be their alternative. This took place in Damascus, and always recurs with such inferior emirs.

http://97.105.52.213/en/artical/20819/decision-was-to-flee