Civilization-level rallying can override doctrinal divisions within a civilization.

Evidence

The broadest and most effective civilization rallying was by the Muslim world on behalf of the Bosnian Muslims. The Bosnian cause was universally popular in Muslim countries; aid to the Bosnians came from a variety of sources, public and private; Muslim governments, most notably those of Iran and Saudi Arabia, competed with each other in providing support and in attempting to gain the influence that generated. Sunni and Shi’ite, fundamentalist and secular, Arab and non-Arab Muslim societies from Morocco to Malaysia all joined in. — Samuel P. Huntington, The Clash of Civilizations and the…, 788