The Quranic concept of Ummat al-Mu’minin (colloquially, the Ummah) or the Commonwealth of the Islamic believers, was never really united historically, isn’t so now, and is unlikely to be so either, looking at the sectarian divide that besets the Islamic world.
While Ummah literally translates to ‘nation’ in Arabic, history is instructive of ‘divides’ within, which ensure that regionalism, culturality, ethnicities or sectarian pride practically triumph over the collectiveness of the generic concept, Ummah, for Muslims.
Attempts like the United Arab Republic (pursuant to championing of Pan-Arabism by Gamal Nasser), a sovereign state created between 1958-61, encompassing Egypt and Syria, soon imploded owing to regional one-upmanship. Closer home, the purported ‘land of the pure’ and the only country to be created in the name of religion, Pakistan, tore into two distinct parts in 1971; the regional and cultural pride of the Bengalis was at the heart of animosity between the dominant West Pakistan, and the then East Pakistan.
Today, despite all the rote platitudes of ‘brother Muslim country’, Afghanistan and Pakistan are engaged in a bloody face-off that has led to more killings on the restive Durand Line (Af-Pak border) than the tensions due to the traditional enemy across the Line-of-Control (read, India). It is believed that more people have died in Af-Pak clashes in recent times, than all the Pakistani casualties put together in all Indo-Pak Wars.