Thousands of mathematicians are refusing to attend this summer’s International Congress of Mathematicians in Philadelphia, citing risks to international scholars under Trump administration immigration enforcement. The boycott petition has topped 3,000 signatures ahead of the July event, raising questions about whether the U.S. can still safely host major academic gatherings.
The International Congress of Mathematicians meets every four years. It draws researchers from across the globe to share breakthroughs, debate ideas, and award the field’s most prestigious honors. This year’s event runs from July 22 to 31 in Philadelphia. But as the date approaches, the conference is bleeding participants.
As reported by TV2, more than 3,000 mathematicians have signed a petition refusing to attend. Their reason is straightforward. They believe the United States under the current administration poses a direct threat to international academics, particularly those from vulnerable regions or traveling on non-citizen visas.
I have watched Denmark grapple with its own immigration debates for years. But what is happening in the U.S. right now is on a different scale. Since Trump’s second inauguration in January 2025, Immigration and Customs Enforcement has ramped up arrests and deportations with an intensity that has sent shockwaves through academic communities. ICE raids in courthouses, on campuses, and even in immigration hearing hallways have become routine. Videos from June 2025 showed agents making rough arrests in elevators and corridors. For scholars traveling internationally, this creates not just inconvenience but genuine fear.
From Street Protests to Academic Boycotts
The mathematician boycott does not exist in isolation. It is part of a broader wave of resistance that has been building since early 2025. The so-called “No Kings” rallies, organized by groups including Indivisible and the ACLU, have drawn millions into the streets. On April 11, 2026, an estimated 8 million people participated across 3,300 events in the U.S. and Europe. St. Paul alone saw 200,000 protesters. These demonstrations began as protests against mass deportations but have expanded to challenge what participants see as authoritarian overreach.
Living in Denmark, I have seen how Trump’s rhetoric on Greenland sparked outrage here. But Americans and international allies are now organizing around domestic policy as well. The mathematician boycott reflects a similar calculation. If hosting a conference in the U.S. means some colleagues cannot safely attend, then the venue itself becomes a political statement.
The early ICE raids in Los Angeles began on June 6, 2025, with 45 arrests. By June 10, New York City alone had seen 110 arrests over two days. National Guard deployments followed, with 2,000 troops in LA on June 7 and an eventual total of 4,000 across California. Marines were activated as well. Street protests turned violent in some cities, with tear gas deployed in Denver and roadblocks shutting down major thoroughfares.
What This Means for International Collaboration
The International Mathematical Union, which organizes the Congress, has not yet issued a public response to the boycott. That silence is itself telling. The petition argues that holding the event in Philadelphia endangers lives and careers. One organizer stated that hosting in the U.S. now risks the safety of international attendees. For mathematicians from countries with strained relations with Washington, or for those holding temporary visas, the calculus is simple. Skip the conference or risk detention.
This is not just about one event. It raises a broader question about whether the United States can continue to host major international gatherings under current conditions. Academic conferences depend on free movement of ideas and people. When scholars from certain countries or visa categories start declining invitations, the intellectual exchange suffers. I have seen how geopolitical tensions can complicate even routine travel. Now multiply that uncertainty across thousands of academics trying to make summer plans.
For expats like myself, this hits close to home. Many of us have moved across borders for work or family. We understand visa anxieties and the constant low-level stress of proving you belong. Imagine layering onto that the threat of arbitrary detention or deportation. It is no wonder scholars are choosing to stay away.
The boycott also mirrors actions inside U.S. institutions. In March 2025, Democratic lawmakers disrupted Trump’s joint address to Congress with signs reading “This is NOT Normal” and “FALSE.” Representative Al Green was removed for shouting during the speech. These gestures, like the mathematician boycott, signal organized resistance from within traditionally neutral spaces.
What Happens Next
As of today, the petition continues to gain signatures. Whether it will force a venue change remains unclear. The International Mathematical Union may prioritize institutional neutrality over the demands of boycotters. But the damage to the event’s credibility is already done. Reduced attendance will mean fewer presentations, weaker networking, and a less representative gathering.
The broader consequences extend beyond one conference. If international academics begin avoiding U.S. venues systematically, American universities and research institutions will feel the impact. Collaboration depends on trust and access. Both are eroding fast.
Sources and References
The Danish Dream: Trump’s Greenland Remarks Spark Danish Outrage
The Danish Dream: Why Does Trump Want Greenland? What You Need to Know
The Danish Dream: How to Move to Denmark from USA Without Stress
TV2: Flere tusinde matematikere boykotter kongres i protest mod Trump
