In the next decade, in addition to continuing as a state-of-the-art astrometric tool for planetary defense, we expect ground-based radar observations to expand our knowledge of the physical characteristics of the near-Earth asteroid population in terms of their shape, binarity, and near-surface structure. We recommend that facilities with ground-based radar systems, planetary radar programs, and research and analysis of radar observations receive full support from NASA and NSF to ensure their availability to the planetary science community and as a resource for planetary defense initiatives through the next decade.