Since the Egypt-Israel peace treaty was signed in 1979, Washington has given Cairo more than $50 billion in military grant aid. But a strong military relationship has raised as many questions as it has answered: about the ethics of working with an increasingly harsh authoritarian government; about the partnership’s success in achieving American interests in the region; about the Egyptian military’s willingness to reform; and about whether conditioned aid can spur political change. Correspondingly, the post–Arab Spring years have seen rough patches, caused by U.S. limitations on military aid following the 2013 overthrow of Mohamed Morsi, America’s chafing at Egyptian human rights abuses, and Cairo’s eventual turn toward less restrictive partners such as Moscow and Paris for military supplies.