Group photo from the 1924 International Congress of Mathematicians meeting on the University of Toronto campus.

Dear Colleagues,

I am reaching out in anticipation of the upcoming ICM in Philadelphia this summer. The ICM remains our discipline’s most significant gathering ­– an opportunity to share ideas, recognize achievement and reaffirm the international character of mathematics itself. We at Fields look forward to attending every four years to see colleagues and celebrate emerging talent.

I also wish to acknowledge, directly and respectfully, the concerns that many members of our community have expressed in light of the current political climate. These concerns are real, and it would be neither responsible nor honest to suggest that any organizing committee can fully control or eliminate broader political or social uncertainties. What I can say is that, after numerous conversations with the ICM’s organizers, I recognize and acknowledge their commitment to doing everything within their remit to foster a respectful, supportive and professionally focused environment for all participants, and can assure you they are working closely with local partners to support the smooth running of the Congress.

This moment is not without precedent. Just over a century ago, in the aftermath of the First World War, deep political divisions and exclusions threatened the future of the International Mathematical Congress itself. It was in that context that John Charles Fields worked tirelessly to preserve the Congress as a genuinely international enterprise. Recognizing that mathematics could not thrive in isolation or fragmentation, he helped move the Congress beyond Europe for the first time, allowing it to survive and ultimately to flourish. From this same vision came his proposal for a new kind of recognition, what we now know as the Fields Medal, intended as a forward-looking investment in the shared future of mathematics.

The ICM has endured and thrived precisely because mathematicians have chosen engagement over withdrawal, and presence over absence, even when circumstances were imperfect or fraught. In times when political forces strain international collaboration, the Congress has served as a space where our common intellectual commitments remain visible and alive.

Gathering in Philadelphia is, first and foremost, an academic act. But it is also a continuation of this longer tradition: a reaffirmation that mathematics is built through sustained international contact, mutual respect and shared effort. The strength and character of the ICM has always depended on the willingness of mathematicians to show up, contribute and stand together as a global community.

I therefore encourage you to join me at ICM 2026. Your participation matters ­– not only for the scientific vitality of the meeting, but for the continued health and unity of our shared institutions. I believe that the most meaningful way to honour the legacy of the Congress is to keep the international conversation going.

Sincerely,

Deirdre Haskell