The Family Of Imran - 3:165 "You said, "Why is this also?"when you inflicted (on your enemy) double the damage you had suffered. Say, "(That) calamity is from your own side."Allah is Omnipotent."
The damage they have suffered and why:
The Family Of Imran/3:152 Allah kept His promise to you, and indeed you destroyed them by His permission. But after He showed you what you loved, you hesitated and quarreled among yourselves about the war and did not listen to the orders. Some of you wanted the world and some the Hereafter. Then He turned you away from them as a test and forgave you in spite of everything. Allah is bountiful to those who believe
The Family Of Imran/3:153 You were climbing the hill without looking back at anyone, although the Messenger called you from behind. He gave you sorrow upon sorrow so that you might not grieve for what you had lost and what had happened to you. Allah is All-Knowing of what you do.

The Repentance/9:25 Allah helped you on many occasions. On the day of Hunayn you were proud of your numbers. But your numbers did you no good. Indeed, the earth became narrow for you despite its vastness and you turned and fled.

The Coalition/33:9 O you who believe, when armies attack you, remember the favor of Allah, Who sends upon you a wind and armies that you do not see. Allah is All-Seeing of all that you do.
The Coalition/33:10 They attacked you from above you and from below you. And the eyes were turned, and the hearts were in their mouths, and you were harboring various doubts about Allah.
The Coalition/33:11 The believers were tried there and shaken violently.
The Coalition/33:12 "The hypocrites and those whose hearts were diseased were saying: "The promise of Allah and His messenger to us is nothing but a pipe dream!"
The Coalition/33:13 "A group of them were saying, "People of Yathrib, you cannot hold on any longer; go back."The other group of them were asking permission from the Prophet, saying, "Our houses are unprotected,"even though their houses were protected. Their whole purpose was to escape."
The Coalition/33:14 If it had been occupied and they had been asked to join the enemy, they would have joined them without hesitation.
The Coalition/33:14 If it had been occupied and they had been asked to join the enemy, they would have joined them without hesitation.
The Coalition/33:15 They had promised Allah before that they would not turn their backs and flee. Every promise made to Allah will be questioned.
The Coalition/33:16 "Say, "Fleeing from death or war will not benefit you. Even if you flee, you will not live long."
The Coalition/33:17 "Say, "If Allah wills for you an evil or a mercy, who will protect you against Him? They will not find any protector or helper besides Allah."
The Coalition/33:18 "Allah knows those among you who hinder and those who say to their brothers, "Come to us". They seldom join the defense."