Empire-builders in early America took Middle Eastern deserts as a key source of inspiration colonizing the arid lands of southwestern North America. Anglo-American settlers struggled to make sense of the region’s human and physical geography, but quickly began to interpret the desert Southwest as a local version of the Middle Eastern deserts they imagined through the Biblical Orient. But as U.S. empire started to expand beyond North America, settlers and their descendants learned that they could sell their new desert “expertise” abroad, and started to build new colonial networks in the Middle East around the stories of their common arid lands experiences. Based on extensive archival research and fieldwork, this paper surveys the long history of desert exchange by focusing on ties between Arizona and the Arabian Peninsula that began in the 1800s. It shows how the domestic cultures of arid empire, rooted in the U.S. Southwest, transformed into an important channel of international cultures of arid empire that started to diplomatically bind the U.S. and the Gulf from the 1940s on. With the transformation of US-Gulf relations over time, the desert imaginaries that defined their imperial entanglements also evolved – shifting away from older Biblical narratives and more toward the technofetishism of modernist science that became a defining feature of U.S. cultures of empire after WWII. Taking one example from this history, the paper shows how the “desert” as an environmental imaginary figured in the University of Arizona Environmental Research Laboratory’s joint greenhouse/desalting plant, initiated in Abu Dhabi in 1968. As an early example of the high-modernist, spectacular (geo)engineering projects now familiar in the Gulf, the Arizona-Abu Dhabi project illustrates how the very idea of the “desert” – and its “natural limits” to extractive financial and political systems – becomes a narrative resource to justify precisely those extractive systems. Cultures of arid empire are thus built as elites and arid lands “experts” breathe life into their stories of the desert, which are then put to work in the service of imperial visions based on extractive approaches to the land, environment, and human beings. The “desert” is constantly reinvented by these actors, as they learn to use it in new and unexpected ways. And this is the story of empire itself.