All these movements indicate that the Prophet was extremly...

All these movements indicate that the Prophet was extremly worried about the north and he predicted that Islam would be attacked by the Roman state. The other side of this triangle of enmity was the Sassanid Kingdom of Iran. This enmity was so bitter that Khosro Parviz tore up the Prophet's letter in rage and killed the Prophet's ambassador and wrote to the governor of Yemen to kill the new Prophet and send his head to the Madaen court! Hijaz and Yemen had long been colonies of Iran.

But then, due to the advent of Islam the two gained independence and it was probable that the two states stage attacks against Iran. Although Khosro Parviz passed away while the Prophet was still living, the separation of Yemen and Hijaz and their shores was always in the minds of the kings who reigned after Khosro Parviz, who were worried about the new power whose troops were equipped with faith, sincerity and unity.

With such powerful enemies, could the Prophet pass away without having nominated a political successor for himself? Reason would not allow us to attribute such negligence to the Prophet. [^1]: . Quran 52:30. [^2]: . Al–Darajat Al–Rafiah, p. 77. Ali (as) expressed his ideas concerning Abu Sufyan with the following statement. ما زلت عدوّ الإسلام وأهله "you have always been an enemy to Islam and Moslems". Refer to "Al-Esty’ab" vol. 2 / p. 690. [^3]: . This narration has been repeated frequently.