Is it permissible for a Saudi Muslim to kill a Crusader by treachery because America made an un-Islamic treaty with Saudi Arabia?

The questioner : The second question: Is it permissible for a Saudi Muslim to kill a Crusader by treachery? We know and have learned that a treaty or agreement must be lawful. America agreed with Saudi Arabia on an unlawful agreement, which is invalid. Since this agreement is invalid, is it permissible for me to be treacherous to this American so that he does not kill that Muslim?

The Shaykh : It is not permissible. Because if one wants to say this agreement is invalid, why does he ratify it? He must cancel it on one hand. He ratifies it and acknowledges it, and on the other hand, he says, "Since this agreement is invalid, it is permissible for me to fight or kill this American, or British, or other foreign countryman." Here, I must...