One of the most contentious issues in early Islamic history is the matter of the allegiance (bay‘ah) of Amīr al-Mu’minīn Ali (a) to Abu Bakr. This research, employing an analytical-critical approach and relying on credible historical, hadith, and theological (kalāmī) sources, investigates three fundamental dimensions of this issue: first, the concept and conditions for the realization of a valid allegiance and the extent of its correspondence with the events following the passing of the Prophet (s); second, an analysis of the wisdom and the socio-political dimensions of Imam Ali’s (a) delay in giving allegiance; and third, an examination of the narrative meaning of the "apostasy" (irtidād) of the Companions and its relationship to the event of Saqifah.
The findings indicate that in legal (fiqhī) and historical sources, allegiance has specific conditions and requirements that render its realization contingent upon the individual's genuine free will (ikhtiyār) and the acceptance of the other party's legitimacy; any deficiency in these prerequisites nullifies the validity and legitimacy of the allegiance. An examination of historical evidence shows that these conditions were not observed in the case of Imam Ali (a); thus, the realization of allegiance according to valid criteria was not possible. Given the sensitive conditions following the Prophet’s (s) death and the threats that could have disintegrated the Islamic society—providing grounds for the dominance of enemies and disbelievers—Imam Ali (a) engaged in a form of compromise with Abu Bakr to preserve Islam and prevent the squandering of the Prophet’s (s) extensive efforts. This action was taken solely to secure the overarching interests of the faith and to prevent harm to the Islamic community; it never signified the acceptance of the legitimacy of his caliphate. Even if some reports interpret "allegiance" merely as "shaking hands," this act was also performed under compulsion and constraint (ikrāh) and lacks validity and legitimacy. Therefore, the allegiance of Imam Ali (a) to Abu Bakr, even if it ostensibly occurred, is neither valid nor can it serve as a basis for proving his caliphate.
Historical evidence and the analysis of the conditions of that era demonstrate that any external action can only be understood as an emergency compromise to preserve Islam and prevent damage to the Islamic community, rather than an acceptance of political legitimacy. Furthermore, the delay in allegiance was a purposeful act to proclaim the Imam's legitimacy and to negate the legitimacy of the Saqifah caliphate; subsequent cooperation can only be explained within the framework of the supreme interests of preserving Islam. In the third axis, a contextual and comparative analysis of the narrations shows that the concept of apostasy in Imami culture refers to the violation of the covenant of Wilāyah, not a legal departure from Islam. The synthesis of these three dimensions demonstrates that the structure of Abu Bakr's caliphate, from the perspective of Imam Ali (a), lacked legitimacy and was based on mechanisms that are regarded in historical sources as instances of exercising illegitimate and despotic authority. This research provides an integrated and documented re-reading of the issue of allegiance and its consequences by synthesizing historical, theological, and hadith data.