Political parties are key instruments in achieving power in a representative democracy. This is the main reason why governments and political elites in all countries are highly sensitive to the cooperation of foreign actors with political parties. Understandably, these governments are opposed to outside influence affecting their domestic power structures. However, political parties are not just instruments to achieve power in a representative democracy. Their structures and activities are also highly relevant for the inclusivity and stability of a representative democracy. If they are disorganized or dysfunctional, the quality of the democratic order, including government accountability and the respect and promotion of human rights, is negatively affected. These two fundamental observations create a dilemma for the EU in its agenda to promote democracy and human rights in its external action: if the EU excludes political party cooperation from its programs and activities, it cannot achieve important objectives in the field of democracy and human rights. If the EU includes political party cooperation, it risks running into serious conflict with the respective host countries’ governments and political elites. Beyond democracy and human rights, EU engagement in political party cooperation can offer opportunities for promoting constructive partnerships in the areas of peace and security, climate change and disaster prevention, the management of migration, or other thematic fields. Political parties are the key channels through which current and future leaders develop both their understanding of policies and original ideas. Through political party cooperation programs, the EU and European stakeholders develop trusting and supportive relationships with future political leaders, irrespective of the ruling government and any potential political changes.