For a decade, surface force measurements in ionic liquids showed screening lengths far longer than Debye theory predicted. The anomaly was real in the data. The question was whether it was real in the physics.
Gaddam and Ducker resolved this by measuring extremely slowly. They approached surfaces at velocities as low as 9 picometers per second with equilibration times of up to 90 seconds. At these glacial speeds, the long-range repulsion that had generated hundreds of papers shrank in both magnitude and range, with decay lengths converging ultimately to screening lengths consistent with classical Poisson-Boltzmann theory.
The anomaly was a non-equilibrium artifact. Fast surface displacements push ions out of equilibrium faster than they can reorganize. The displaced ionic structure generates a repulsive force that looks like anomalous underscreening but is actually the system's sluggish response to being measured too quickly. The transition unfolds over nearly two orders of magnitude in time, with slow relaxation dynamics reminiscent of aging phenomena in glassy materials.
The field measured what it created. Every surface force experiment implicitly assumes the system reaches equilibrium before the measurement is recorded. In a conventional electrolyte with small, fast ions, this assumption holds. In an ionic liquid where every particle carries charge and reorganization requires cooperative rearrangement of dense ion networks, the assumption breaks precisely when the system is most interesting.
The screening was always short-range. What was long-range was the measurement's perturbation of it.