"As you may imagine, my family has experienced enormous stress and uncertainty during this period, and I keenly feel the need to resolve our situation," wrote Tariq Ramadan, a high-profile Swiss theologian who publicly opposes violence in the name of Islam.
In a statement, the university said Ramadan was abandoning the tenured appointment in classics and peace studies as a result of the State Department's invocation of an anti-terrorism law last summer to keep him out of the country.
State Department spokeswoman Angela Aggeler told the Washington Post the details behind what is known as a "prudential revocation" remain confidential.
Ramadan, 42, is viewed in intellectual circles as a scholar who seeks to bridge the Western and Muslim worlds, arguing a Muslim can be a full participant in both. A scholar of Friedrich Nietzsche and the Koran, he is the author of more than 20 books, including the most recent, "Western Muslims and the Future of Islam."