Western governments have been accused of turning their backs on scholars who are under threat in their home countries, risking damage to their own university systems in the process.
The warning was voiced by senior academics including Anne Lonsdale, former deputy vice-chancellor of the University of Cambridge, who said that governments and international agencies needed to "wake up" to what was going on.
Speaking last week at the British Academy in London, Ms Lonsdale, who is chair of the Council for Assisting Refugee Academics (Cara), said that in many countries the persecution of scholars was getting worse.
Since 2003, more than 350 academics have been murdered in Iraq alone, and many more have been kidnapped.
Academics who are under threat there and elsewhere, she said, "struggle to get to Britain - or would, if the visa regime allowed them to".
She argued that it was a "huge waste" if refugee academics remained unemployed in the countries they fled to, noting that a scheme in the UK to get such scholars back into work had recently closed after losing funding from the European Refugee Fund.
Ms Lonsdale was speaking at an event to launch a new book, In Defence of Learning: The Plight, Persecution, and Placement of Academic Refugees 1933-1980s, edited by Shula Marks, Paul Weindling and Laura Wintour. The book is based on a conference held at the British Academy three years ago to mark the 75th anniversary of Cara - originally the Society for the Protection of Science and Learning, set up in 1933 to aid academics under threat in Nazi Germany.
Contributors also explore the impact on British academic life of waves of refugee scholars from Austria, the Soviet Union, Czechoslovakia, South Africa and Chile.
Sir Adam Roberts, president of the British Academy, spoke of the "almost incestuous number" of Cara-assisted refugees who had gone on to become Fellows of the academy.
The book is a timely reminder of the contribution academic refugees make to learning all over the world, he said, adding that Cara's work is as important now as when it was founded.
Sir Adam went on to bemoan "the extraordinary ways the UK border agencies deal with foreign academics and students", which, he said, made Cara's work "far more difficult".
Professor Marks, one of the editors of the book and professor emeritus of South African history at the School of Oriental and African Studies, noted that "the history of Cara, to some extent, tracks the geography of tyranny".
"The persecution of academics is often the first sign of wider persecution, if not genocide," she said. "Academics were rescued in the 1930s in no small part due to the foresight of British academics and the generosity of British universities and learned societies."
Yet Professor Marks feared that "Americans and Europeans are becoming increasingly inhospitable, even to academic refugees".