Dean completed his PhD from Liverpool John Moores University in 2019, with a thesis on US activism and the transnational dimensions of the Congo reform movement. His research interests are in the field of activism, particularly on movements and organisations whose activities transcend national boundaries, with a specific focus on how activists coordinate and the impact of their activism on government domestic and foreign policy.
Recently, he has begun work on a project examining the environmental movement in the United States during the late nineteenth and early twentieth century. This work examines the impact of the activism of conservation organisations on the internal debates on domestic and foreign policy decision-making in the US, focusing on their advocacy for the establishment of state and national parks as a way to protect natural areas for public use, and the consequential impact of this in promoting a sense of American identity to highlight the environmental movement's contribution to the development of a more complex and nuanced vision of US empire, one that recognised the importance of stewardship and conservation as well as economic and military power. Focusing on themes such as preservation, conservation, economic justice, immigration issues, race, and questions over social democracy, this project will also draw connections between this and more broader themes, such as the movement's role in adopting European initiatives to protect remnants of historic civilisations either within the US or its colonial territories, and on the imperial dimensions to the conservation project and its efforts to take the conservation crusade into the international arena.