Denmark's higher education institutions are increasingly rejecting foreign researchers due to heightened concerns over espionage, particularly from Russia, Iran, and China. Aarhus University has rejected 24 applicants this year, citing risks of sensitive research being compromised. The Danish Security and Intelligence Service warns of various methods foreign states may use to exploit researchers. The situation is exacerbated by Denmark's EU presidency and the rising threat of cyber espionage, leading to a cautious approach in hiring foreign talent.