Nationalism has experienced a resurgence across Europe since 1980, and one common explanation for this resurgence is that the backlash to European integration aids radical right parties, which prioritise nativism in the form of anti-immigration and anti-ethnic minority appeals. In contrast, I argue that historical changes to EU governance in the late 1980s and early 1990s means that European integration has instead undermined identification with the central state, as it encourages ethnoregionalism, which seeks either greater autonomy or independence for a sub-national unit. In addition, these reforms mean that the EU also reduces the saliency of external exclusiveness appeals, which focuses on reclaiming people and territory in neighbouring countries. This appeal can range in intensity from aiding purported conationals, to arguing that these kin or territory should become part of the state. My theory operates through parties' vote-seeking incentive, as these reforms have altered the ease with which parties can convince voters of the feasibility and desirability of each appeal. I test this theory by examining how nationalist parties combine both nativism and ethnoregionalism, and the relative saliency that they attach to each. Through a quantitative analysis of party manifestos across 32 European countries for 1980-2019, I find that European integration has a significantly stronger effect on the saliency of ethnoregionalism than nativism. Furthermore, to demonstrate that the causal mechanism operates as expected, I also utilise a qualitative process-tracing analysis of the EU's effect on the appeals utilised by Italy's Lega and Belgium's Vlaams Belang, which together constitute a most-different systems and diverse case design. Finally, using qualitative process tracing for the most different systems and diverse cases of Ireland and Hungary, I find that the EU has reduced the saliency of