Besier's publications have focused on church history, including church history during the Third Reich and the German Democratic Republic,[1] and religious freedom issues in contemporary society.

His views on religious freedom follow the libertarian American model, a stance which has made him controversial in Germany.

From 2003 to 2008, he was the director of the Hannah Arendt Institute for Research on Totalitarianism at Dresden University; his contract was not renewed following widespread criticism in Germany of his liberal views on Scientology.

[6] He is a visiting professor at universities in the United States, Sweden and Poland, and is the editor of Kirchliche Zeitgeschichte, an academic journal on church history.

Formerly considered close to the conservative Christian Democratic Union party, Besier joined the left-wing Die Linke party in April 2009, and was nominated for a safe Landtag seat in Saxony.