1. United States
2. N.D.
3. Letter

It is deeply concerning to see the chilling effect of restrictive immigration policies on international scientific collaboration and the free exchange of ideas. The cases highlighted – from the deportation of researchers to the detention and denial of entry for others – threaten to undermine America's global scientific leadership. Obstructing the flow of talent across borders will ultimately harm scientific progress in the United States and weaken its research institutions. This crackdown is already dissuading foreign scholars from traveling to the U.S. for conferences, collaborations, and field work out of fear they may face interrogations, device searches, or even deportation – despite having proper documentation. American scientists who are not citizens also feel forced to reconsider travel that could put their re-entry into jeopardy. Such an environment of anxiety and suspicion poisons the open discourse so vital to the scientific enterprise. These policies send an unwelcoming message that could make the U.S. less attractive to top international students and researchers. Sustained brain drain would be deeply damaging for American universities and labs striving to tackle complex global challenges. Prioritizing national security in this manner risks hollowing out America's scientific and technological competitiveness in the long run. A course correction is urgently needed to protect U.S. interests and reassure the world's scholars that they will be treated with respect when attempting to engage in professional activities stateside. Overly aggressive border screening and ideological litmus tests have no place in facilitating the cross-pollination of ideas so essential to pioneering research. American science and society stand to lose immensely if this crisis of confidence is allowed to escalate further.