Dear Members of the U.S. Crystallography Community,
We are at a pivotal moment for U.S. structural science. The National Academy of Sciences (NAS) has announced that, effective January 1, 2026, it will withdraw from the International Union of Crystallography (IUCr) and dissolve the U.S. National Committee for Crystallography (USNC/Cr). This action ends a long tradition of national representation and threatens the continuity of U.S. engagement with the global crystallography community.