Is it okay to break a covenant of protection against a harbi?

Question

Breaking promises is obviously haraam in general, but the Harbi is the one who is at war against the Muslims, and

Allah's Messenger (ﷺ) said: “War is deceit" [ Sunnah ref: Sahih Bukhari 3029 ]

So does this mean its okay to be deceitful in promises with those at war with muslims? For example, promising a Harbi protection but then just ending him anyway.

Answer 1

No it is not. 9:4 and 9:7 specifically command us to fulfil our covenants with the Harbi disbelievers, as long as there is no betrayal from their side.

Imam Nawawi writes in the sharah of the hadith الحرب خدعة (War is deceit) that:

واتفق العلماء على جواز خداع الكفار في الحرب وكيف أمكن الخداع إلا أن يكون فيه نقض عهد أو أمان فلا يحل

The scholars are in agreement that it is permissible to deceive the disbelievers in war whenever it is possible, except when it involves violation of a treaty or aman (asssurance of safety) in which case it is not lawful

^{— Fath al-Bari and Sharah Muslim}