Just before Muhammad death we see almost all parts of the Arabian Peninsula condemning Obedience to him, and even the Arab countries that were never subject to a prince of.
Before, appear in political unity and subject to the will of an absolute ruler These diverse tribes, small and large, with different elements Which may reach its mass and which has not ceased to conflict and conflict, created a message Muhammad is one nation, and the idea of common religion has been united under one leadership. The various tribes in one political system, the system whose advantages prevailed at an astonishing speed and admiration; and that one great idea was to achieve this result, that is the principle of national life in the pagan island of Arabia, and so was the tribal system for the first time, (As it was impossible), something secondary to a sense of religious
unity.
The great task was successful. When Muhammad moved to his Lord, tranquility fluttered over the largest area of the Arabian Peninsula, which the Arab tribes had never known before, with the intensity of its attachment to destruction and taking revenge. It was the Islamic religion that paved the way for this coalition

– Thomas Arnold, English Orientalist
(In his book call to Islam)