Al-Mamoon's Objecive Behind Regency

As regarding his request that the Imam should accept to be the caliph after he himself abdicates, his objective was more than just proving to the public that the Imams from the Ahl al-Bayt (A.S.) were certainly after the glory of this life, coveting it, and that their asceticism and distancing themselves therefrom was only because they were unable to reach their worldly goals as some stories claim96 and on which yet other conclusions are based.

The Imam, in fact, did not underestimate the power to rule nor did he willingly stay aloof from its responsibilities; how could he do so while viewing himself as more worthy of the post of the supreme ruler and more capable than him in managing its affairs with equity? The fact is that he was confident that such thing would not happen for him, and that the whole matter was a clever political trick performed by al-Mamoon which he wanted to carry out by using Imam al-Rida (A.S.) as a ploy. When al-Mamoon offered to abdicate the throne for the Imam, he was calculating the matter to end up with one of two cases: either the Imam would agree, or that he would refuse, and in either case, he would gain for himself and for the Abbaside government a victory, for the Imam's agreement would be preconditioned upon accepting that he, al-Mamoon, would be named the regent, thus securing the legitimacy of his own caliphate after the Imam before all parties; otherwise, al-Mamoon was not so naive or short-sighted to the extent that he would offer his own post on a silver platter to the Alawides and become a subject dealt with as such. If al-Mamoon came to be a regent, it would be easy for him to put an end to the life of the Imam in order to succeed him without anyone finding out, thus satisfying the ambitions of the Alawides for the government while convincing their Shi'as of his own legitimate caliphate. Al-Mamoon had his own particular methods in eliminating his political foes, and we will mention the mysterious method he employed to put an end to the life of Dhul-Riyasatayn al-Fadl ibn Sahl and his murder of those who killed him despite their admission that he was the one who incited them to assassinate al-Fadl.

As regarding the case of the Imam refusing to accept the caliphate, this, al-Mamoon calculated, would cause him to be very widely criticized by his own Shi'a followers and companions due to their own belief that caliphate was rightfully his and he had to accept it, but the Imam's companions were endowed with a great deal of political awareness to the extent that they would not be tricked by a trick like that carried out by al-Mamoon. Also, he would be excused by various Shi'a factions for not accepting it for himself and his family, and that he tried so but could not succeed and thus would silence those who might dispute with him in this regard from Shi'a opposition groups.

Adapted from: "Imam al-Ridha (a.s.), A Historical and Biographical Research" by: "Muhammad Jawad Fadlallah"