AbstractLegal scholars are familiar with the problem of executive overreach, especially in emergencies. But sometimes, instead of being too audacious or extreme, a national executive's attempts to address a true threat prove far too limited and insubstantial. In this Essay, we seek to define and clarify the phenomenon of executive underreach, with special reference to the COVID-19 crisis; to outline ways in which such underreach may compromise constitutional governance and the international legal order; and to suggest a partial remedy.