The European migrant crisis that started in 2015, just like the economic crisis that preceded it, has brought the limits of European solidarity into broad daylight. However, where EU integration showed its limits and Member States struggled to agree on sharing the burden, civil society started leading by example. From organising donations to opening their homes to migrants in need, citizens showed initiative while officials seemed reluctant to act. Seeing civil society getting to grips with such crises is certainly a source of inspiration, but it also calls for a systematic analysis. What makes citizens want to enforce European solidarity? How can we make the most of such willingness? How can governments and EU institutions support and complement civil society initiatives? The TransSOL (European paths to transnational solidarity at times of crisis: Conditions, forms, role-models and policy responses) project aimed to answer these questions by providing the first rigorous and comprehensive analysis of transnational solidarity in Europe. Why focus this project specifically on times of crisis? Christian Lahusen: A project dealing with European solidarity must address the various crises affecting citizens. The Great Recession, the so-called migrant crisis and Brexit have caused serious problems and conflicts within and between European Member States. We’ve reached a point where the very concepts of European cohesion and solidarity are in crisis. There is, however, a growing mobilisation of citizens and civil society. The TransSOL project was particularly interested in these civic expressions of European solidarity: we wanted to map and analyse them, and to draw lessons in terms of inhibiting and beneficial factors. Which aspects of solidarity did you consider and why? Our project assumes that solidarity is a multidimensional phenomenon. Painting an adequate picture of European solidarity therefore implies the consideration of its various expressions: charitable and altruistic activities, of course, but also political advocacy. We could show that solidarity is organised at different levels: individual citizens and interpersonal networks; civil society and organisational networks; and national welfare state and public debates. Besides, in normative terms, we have seen that although solidarity is a universal principle bridging communities, countries and continents, it is often tied back to specific constituencies and communities and therefore limited to members of specific groups such as nation-states or ethnic groups. Solidarity can indeed be inclusive when involving a fight for the rights of distant groups, but solidarity can also be strongly exclusive, when help and support are restricted to those being part of one’s own community. Solidarity is a highly politicised and contentious norm, meaning that we must also analyse the ways solidarity is used by different, possibly opposing groups. How did you proceed to conduct your research? We started by developing research tools to map and analyse solidarity at its various levels of aggregation. We conducted a population survey to investigate individual solidarity, engaged in various organisational surveys to reconstruct inter-organisational fields of solidarity within and between European countries, looked at public debates in the mass media, and mapped the role of solidarity in EU and Member State legal and institutional systems. Our research compared three issues (disabilities, unemployment and migration/asylum) to unveil the main contentions and conditions surrounding solidarity. The research was conducted in eight European countries (Denmark, France, Germany, Greece, Italy, Poland, Switzerland, the United Kingdom) and at the EU level. What would you say were your most important findings? We found that a considerable proportion of European citizens endorse the idea of inclusive solidarity and are actively involved in individual activities, both within and beyond their country. Moreover, we witnessed an impressive increase in citizen initiatives as a reaction to the various crises of the EU, showing that the general public is committed to acting as a ‘fire brigade’ in times where governments seem unable to respond appropriately. However, our data confirmed that people tend to limit solidarity to fellow citizens and to those considered trustworthy and deserving. Besides, whilst we have seen strong moments of public inclusive solidarity during the Great Recession since 2008 and the migrant crisis of 2015, the momentum of public solidarity lacked longevity in both cases and was supplanted by regressive tendencies throughout Europe. Civic solidarity therefore requires supportive institutional responses and public policies. Can you provide an example of best practice that you think should inspire future European policy? Several lessons can be drawn from our evaluation of practices and initiatives of transnational solidarity in collaboration with local activists. We can name the importance of being tied back to a local context and constituency, the ability to nurture a decentralised network of local initiatives and activists, the need for communication and translation activities to master the cultural and linguistic diversity of Europe, the combination of offline and online platforms of communication and coordination, and the use of powerful symbols to convey messages. How about your recommendations to policymakers? In general terms, our analyses show that policymakers need to do their homework: citizens have shown repeatedly that they are able and willing to step in when social problems arise. But inadequate policy responses will necessarily weaken civic solidarity, notably in the long term because of over-burden, frustration, counter-mobilisation and/or public defamation. Public inaction might thus threaten the very basis of the European community. More specifically, we see the need to develop European legislation that promotes the development and long-term sustainability of civil society. The European Charter of Fundamental Rights (Art. 12) explicitly grants the freedom of assembly and association at all levels. However, there is a lack of legal infrastructure to realise this right. There is currently no European legal norm for a ‘European association’. Additionally, we propose to recalibrate the balance between Institutional and Project Funding, given that sustainable and stable public financing of platforms is essential to stabilise the organisation and coordination of cross-national solidarity initiatives. What do you hope will be the impact of the project? We expect three types of impacts. Firstly, we expect that citizens and civil society organisations will make use of the knowledge provided by TransSOL in various respects: draw inspiration from the activities of other citizens and initiatives; learn from the way others have acted and organised locally and trans-nationally; and find out how to advocate based on empirical evidence presented in TransSOL. Secondly, TransSOL is raising policy-makers’ awareness of the importance of promoting civic solidarity. Additionally, our empirical findings and policy recommendations pave the way for evidence-based policies. Finally, TransSOL brings about valuable scientific knowledge on transnational forms of solidarity. It also encourages further analyses, thus deepening public knowledge over the long term.