In the 1930s, the disastrous Nazi-fascist policies induced an unprecedented exodus of at least 15,000 intellectuals - scientists and artists, Jews and non-Jews - to the United States. See. e.g., the historical accounts in Adorno, Fleming, & Bailyn: The Intellectual Migration. Europe and America, 1930–1960 (Harvard University Press, 1969) and in Claus-Dieter Krohn: Emigration 1933–1945/1950 (Europäische Geschichte Online, 2011). Names like Einstein, Fermi, Segrè, Von Neumann, Morgenstern, and Gödel are well remembered, as are Adorno, Marcuse, and Fromm, among many others, along with nearly a thousand artists who shaped Hollywood as we know it. Without this immigration, the U.S. would hardly have reached the international scientific frontier in physics, chemistry, and medicine, would not have matured in social sciences, and would have faced greater difficulties in military technological advances (beginning with the Manhattan Project and the development of the atomic bomb).

Today, the policies of the current U.S. administration offer Europe the opportunity to reverse this flow. The Trump administration has imposed massive cuts – both actual and threatened - and even more gravely, to restrictions on research topics (especially in climate and diversity studies) and, more broadly, to limitations on academic freedom in ways reminiscent of "McCarthyism," which imposed significant restrictions on freedom of thought and speech in the 1940s and 1950s under the banner of anti-communism and "national security."

A palpable climate of fear pervades American academia, affecting non-citizen researchers -subject to stricter immigration controls and the constant threat of expulsion - as well as academics at large, who feel their most fundamental professional right - the freedom to research and express themselves - is under threat. An unprecedented battle is underway between the federal administration and Harvard University, extending far beyond the significant funding at stake to challenge academic autonomy itself. The attack on Harvard followed similar actions against Columbia and, as reported by the New York Times, has since targeted Princeton, Brown, Cornell, UPenn, and Northwestern. All signs suggest these attacks are paving the way for an assault on California’s public university system.

A Nature survey revealed that 75% of US scientists polled were considering leaving the country, with the figure rising to 80% among junior researchers. Robert Quinn, executive director of Scholars at Risk, told Times Higher Education (THE) that U.S. higher education is "experiencing unprecedented levels of threats," citing "financial threats" and "state interference in admissions, hiring, teaching content, and institutional hierarchies."

Europe, albeit too timidly, is slowly realising that this setback for international science could be transformed into a tremendous opportunity. In the 1930s, the American art historian William Spencer Cook remarked: "Hitler is my best friend. He shakes the tree, we collect the fruit." In the face of a tragedy incomparably smaller, Europe may still harvest the fruit from the tree shaken by the American administration.

Recently, twelve European research ministers have signed a letter calling for EU-wide initiatives to coordinate efforts to welcome foreign researchers whose work is threatened by political interference and drastic funding cuts. Signatories include Austria, Bulgaria, Estonia, France, Germany, Greece, Latvia, the Netherlands, the Czech Republic, Slovakia, Slovenia, and Spain.

Several European universities have already launched initiatives in this direction. The University of Toulouse has allocated €6 million to host US researchers in biology, health, climate change, and energy. Aix-Marseille Université has announced a plan to raise €15 million to recruit around 15 researchers and has already received over 300 applications, while Université Paris-Saclay aims to fund doctoral contracts and research stays for American academics. Belgium and Norway are also moving forward: Vrije Universiteit Brussel has opened 12 postdoctoral positions with a focus on US researchers, and the Norwegian government is considering measures to facilitate the entry of scientists and students from the US. In Italy, several universities have expressed interest in incentivising the hiring of American talent. On the legislative front, France has proposed a bill to establish the status of "scientific refugee".

On these matters, however, broader initiatives are needed, both by the European Union and individual states. The important appeal of ReBrain Europe, signed by around 2,000 European scientists, aligns with this vision. The document states:"After the Second World War, Europe succeeded in attracting visionary minds and building shared institutions that are now global benchmarks, such as CERN for physics, ESO for astronomy, ESA for space, EMBL for molecular biology, and many others. Today, we can do the same, at a time when top-tier scientific expertise is seeking a new place to operate freely."

ReBrain Europe must now become a priority programme for revitalising research in Europe, with adequate funding at both EU and national levels. We propose that the EU launch a €100 billion fund - financed through Eurobonds - to attract scholars from the US and and the rest of the world and to establish new high-calibre research institutions. While the European Commission seeks €800 billion - also financed through Eurobonds - to build a European military-industrial complex, investing €100 billion in research would send a clear signal of a Europe pursuing also a different path: one of scientific knowledge and academic freedom. ReBrain Europe could bring Europe back to the international technological frontier and fuel long-term economic growth while considering societal impact and environmental sustainability.

From an economic standpoint, this would be an excellent deal. Many studies, see e.g. M. Stamegna, C. Bonaiuti, P. Maranzano, and M. Pianta: The Economic Impact of Arms Spending in Germany, Italy, and Spain (Journal of Peace Economics, Peace Science and Public Policy, 2024), demonstrate that in Europe, the impact of military spending - which relies on components and systems imported from the US - on income and employment growth is far weaker than investments in healthcare and environmental sectors, where Europe excels. Accelerated research spending would offer widespread benefits and set Europe on a high-skill, high-productivity development path.

In parallel to the european initiative, each country could activate research programmes linked to ReBrain Europe and exempt from the budgetary constraints imposed by the European Stability Pact. For Italy, a four-year plan of €3 billion could be allocated to strengthening the public university system, creating new advanced research centres, encouraging the return of Italian scholars currently in the United States and abroad  - 14,000 have emigrated in the past decade -  attracting foreign students and researchers.

Which fields of applied research should be central to  ReBrain Europe? First, the frontiers of information and communication technologies including generative artificial intelligence, quantum computing, a European public cloud, and cybersecurity. Second, medical and pharmaceutical research - focusing on vaccines, antibiotic-resistant bacteria, and anti-cancer treatments. Third, environmental protection - from genuinely "green" hydrogen to technologies for disposing of the countless toxins we release into the environment. But also social sciences and humanities, which remain a European strength and are essential for the quality of our development.

Europe needs to strengthen (where they exist) and build (where they don't) institutions similar to the U.S. National Science Foundation and National Institutes of Health. Italy is even further behind. We have already discussed in a previous article for Scienza in Rete the reduction in university funding and its consequences. We will not repeat those arguments here, but refer readers to the Accademia dei Lincei’s proposal for a 20-year programme (2026–2045) for Italy and Europe, which for Italy echoes the "Ambrosio Report" on fundamental research.

A second pillar of ReBrain Europe should focus on safeguarding and strengthening curiosity-driven, publicly funded basic research, which over the past three centuries has almost always been the source of major advancements in both knowledge and technology.

Europe should have the courage to establish institutions like Princeton’s Institute for Advanced Study, which hosted Einstein, Gödel, and von Neumann, among others—where scientists were not required to produce reports or attend faculty meetings, but only to use their intellect. See the fascinating account by its first director, Abraham Flexner, in Flexner, A. and Dijkgraaf, R.: The Usefulness of Useless Knowledge (Princeton University Press, 2017).

This path naturally requires resisting any attempt to privatise an ever-growing share of research or to place the remaining public research under political control. Certainly, US-based researchers will not abandon the American environment only to find themselves in vaguely similar institutional circumstances.

These are not merely theoretical concerns. The increasing emphasis - now spanning several decades - in Europe on so-called “useful research,” legitimized by the close symbiosis between academia and industry, represents a troubling trend. This is not to suggest that such collaborations are unnecessary or unproductive; on the contrary, they are often essential and yield substantial benefits. However, they should be confined to applied research and must not exert influence over basic research.

Concerns about political control over the public academic system are equally far from abstract. Even in a country like Italy, where research independence is constitutionally guaranteed (Article 33), prominent voices within academia itself have called for some degree of political oversight ("if the state provides the funding, the government should have a say in how it is spent") a position that glaringly overlooks the fundamental distinction between the State and the government. Meanwhile, legislative proposals—fortunately rejected thus far—have sought to compel universities to disclose any information requested by intelligence services.

In the face of the conflict between the Trump administration and U.S. universities, and the opportunities opening for Europe, a bold political and cultural operation with substantial investment is crucial. ReBrain Europe is an opportunity we must not miss.