Understanding the strong nuclear force is one of the fundamental goals of lattice QCD. In addition to shedding light on fine-tuning in nuclear physics, proper treatment of two-nucleon systems is crucial for the calculation of unknown two-nucleon observables, such as neutrinoless double beta decay amplitudes. However, results for this system have been plagued for over a decade by inconsistencies in the literature, pointing to potential uncontrolled systematics in one or more approaches. In this talk I will outline the history and difficulties encountered when computing two-nucleon observables, and present recent progress that has begun to resolve these controversies, leading to a more complete understanding of the systematics involved in two-nucleon computations.