The Islamic Personality by Sheikh Taqīuddīn An-Nabahānī

Muslims can fall into severe situations which compel them to matters which are not allowed but the necessity obliges it. The Islamic State can fall into internal or external crises which compel it to contract treaties which do not lead directly to conveying the da’wah or fighting in the way of Allah (swt) but they facilitate creating conditions which will enable conveying it in the future or prevent the evil of stopping the da’wah or preserve the entity of the Muslims. Necessity compels these types of treaties to be contracted therefore it is allowed for the Khalifah to contract them and they are executed upon Muslims. These treaties occur in two situations which the jurisprudents (fuqaha) stated clearly, and they are:

The first situation: If some people of the people of war seek a treaty from the Muslims for specific years on condition that the people of war give kharaj every year for a specified amount and that the Islamic rules are not executed upon them in their lands; this is not done as it is consenting upon disbelief unless the State is not able to prevent oppression and sees in this treaty good for Muslims, then at this point it is allowed to contract it out of necessity. In this situation there is no assistance or support for them from the Islamic State because they are not compelled by this treaty with the Islamic rules and do not depart from being people of war when they do not obey the rules of Islam. So undertaking support for them is not obliged upon the Muslims. The Messenger of Allah (saw) made a treaty with Yuhanna bin Rub’ah while he was at Tabuk in the boundaries of Bilad AsSham. He left him in his zone upon his religion, and he did not enter under the banner of Muslims and their rule. This treaty of limited period makes the security of this State guaranteed by the Islamic State. Whoever enters it from the Muslims enters it with the security of the treaty and not an individual security, and it is not allowed for him to oppose its people. Whoever enters the Muslim lands from the citizens of this land enters with the security of the treaty and does not require a new security other than the treaty, nor is anyone from the Muslims allowed to oppose him. Traders are not prevented from carrying merchandise to this State except tools used in war like weapons and war materials and what is similar to this because they are people of war even if the Muslims have a treaty with them.

The second situation: This is opposite to the first situation wherein the Muslims pay money to their enemy in return for their silence regarding them. The fuqaha mentioned that if the enemy sieges the Muslims and require a treaty for specified years on condition that the Muslims pay the disbelievers a specific amount every year, it is not correct for the Khalifah to comply to them upon that due to the contemptibility and humiliation therein for Muslims except under necessity. This is (when) the Muslims fear extermination for themselves, and the Khalifah views there is good in this truce. At this point, there is no harm in that due to what was narrated

This indicates that the Messenger of Allah (saw) initially inclined to the truce due to what he sensed of the Muslims’ weakness. When he saw the strength in them due to what S'aad bin ‘Ubadah and S'aad bin Mu’adh (ra) said, he refrained from that which indicates that there is no harm from contracting a treaty with disbelievers paying them money when there is danger of harm. This is because if they conquered Muslims they would take all the wealth and the families as captives (sabaya), so paying some wealth to safeguard Muslims and their families and wealth is less contemptible and more beneficial.