Concerned about Egypt's political instability and the U.S. budget crunch, a growing number of American lawmakers are challenging the wisdom of providing $1.3 billion a year in military aid to Cairo, arguing that the policy is overdue for a wholesale review.

Lawmakers say that Washington's largess, which includes large fleets of M1A1 tanks and F-16 fighter jets, could backfire, given the unpredictability of Egypt's Islamist-led government and its fraught relationship with Israel.

Washington's increasingly controversial aid package to Egypt, a titan in the Middle East, was on the agenda over the weekend when Secretary of State John Kerry met with Egyptian leaders in Cairo. Kerry has argued that disengaging from Egypt would be a mistake, but he will have to contend with louder calls for a review of a policy established decades ago, in a vastly different political context.