[The Persian Empire] left a dream of the Middle East as a unit, and a unit where people of different faiths could live together.

MacGregor is pointing to the Achaemenid Persian Empire’s long afterlife as an idea as much as a polity: a vast, administratively coherent Middle Eastern realm that could encompass many languages, peoples, and religions. The “dream” suggests a remembered model of imperial unity—often contrasted with later fragmentation—where difference is managed through pragmatic tolerance rather than enforced uniformity. In this reading, Persia’s legacy is not only territorial scale but a political imagination of coexistence: an order in which multiple faith communities can live under a single overarching framework. The quote also implies that modern debates about regional identity and pluralism still draw, implicitly or explicitly, on ancient precedents.