The necessity for Islamic union is based not only on the need for a political solution to end the current situation; rather, and more importantly, unity is a requirement of being a Muslim. As in all areas of their lives, Muslims have to abide by the Qur'an's values in their national and international policies. As this morality requires the Islamic world's reunification as a priority, taking Islamic morality as the guiding principle will make this alliance possible, as well as long-lived and active.
Islamic morality requires Muslims to be conciliatory at all times and to be brothers and sisters in faith, as well as in solidarity and union. Allah commands the believers to: "not quarrel among yourselves" (Surat al-Anfal, 46), for doing so will only weaken them. Another verse commands the following:
Do not be like those who split up and differed after the Clear Signs came to them. They will have a terrible punishment. (Surah Al‘Imran, 105)
It is impossible for Muslims who have common sense and conscience not to unite with other believers or to be engaged in an ongoing dispute with them. This is true on an individual basis, as well as on the level of communities and nations. Allah points out this fact in the Qur'an and forbids Muslim nations to be unfair or hostile to one another. The Qur'an states that those who engage in such harmful activity must be stopped, and instructs other Muslim nations to "make peace between them":
If two parties of the believers fight, make peace between them. But if one of them attacks the other unjustly, fight the attackers until they revert to Allah's command. If they revert, make peace between them with justice and be even-handed. Allah loves those who are even-handed. (Surat al-Hujurat, 9)
Of course, there can be cultural, traditional, and local differences of attitude and practice between Muslim nations due to different views, interpretations, and schools of thought. Such things are natural. However, these differences should not lead Muslim nations to antagonize one another, end their mutual dialogue, and consider the other nation as foreign and hostile, instead of agreeing on their common values. Doing so only leads to intolerable situations.
Allah warns Muslims away from such mistakes and reveals the People of the Book's (the Jews and Christians) errors in this respect as an example of what can happen. The Qur'an states in 98:4 that they were divided among themselves even though they received Clear Signs to the contrary. Other verses state that the causes for this split were such evil character traits as envy, injustice, and rebellion against truth. The following are some of these verses:
They only split up after knowledge came to them, tyrannizing one another … (Surat ash-Shura, 14)
The religion with Allah is Islam. Those given the Book only differed after knowledge had come to them, envying one another. As for those who reject Allah's Signs, Allah is swift at reckoning. (Surah Al‘Imran, 19)