In essence, alliance means a contract or covenant made between people in the pre-Islamic era to support one another with regard to everything they did (i.e., irrespective of whether they were right or wrong). Islam canceled such practices, except for the alliances and covenants made to support the truth and prevent the oppressor from his aggression and injustice. It was narrated on the authority of Jubayr ibn Muti‘im (may Allah be pleased with him) that the Prophet ﷺ said: “There is no alliance in Islam.” [Muslim]. This means that Islam disapproves the alliances that contravene the rules and laws of Islam, like what they used to make in the pre-Islamic era. In this hadeeth, the Taabi’ee (a Muslim who saw at least one of the Companions) ‘Aasim ibn Sulaymaan Al-Ahwal asked the Companion Anas ibn Maalik (may Allah be pleased with him) about this hadeeth, and Anas replied that the Prophet ﷺ made an alliance between the people of Quraysh and the Ansaar in his own house. This refers to the bond of brotherhood that he ﷺ established between the emigrants and Ansaar, which was a faith-based alliance that does not fall under the category of the forbidden alliances, because it did not contravene the fundamentals of the Islamic Laws of Islam. The forbidden alliances as per the laws of Islam are those according to which people in the pre-Islamic era of ignorance supported their allies in all cases, even if they were unjust oppressors, taking revenge againsta whole tribe for the killing of one person, and establishing inheritance rights based on such alliances, and the like. However, other alliances, which do not involve these Laws of Islam violations, are allowable in Islam, including supporting the oppressed, fulfilling the religious duties, and similar acts that are recommended by the Laws of Islam, such as fostering friendship, mutual affection, and honoring covenants..