Our support hasn't stopped the successive regimes from taking measures that generate turmoil. Those actions will fuel radical Islamists around the world, some of whom will turn their anger on us.
With its ferocious crackdown, the government may wipe out the Muslim Brotherhood for good. But usually, indiscriminate brutality produces more enemies. One sure result will be to prod Islamists to become more extreme and violent, which could plunge the country into full-scale civil war.
Steven Simon, who worked on the National Security Council under Obama, argued in The New York Times that if we cut off aid, the administration "would be accused by all sides of undermining the country's security and meddling in its affairs." But all sides already accuse us of doing those things, and the more aid we furnish the more credible the charge.
Advocates of the status quo argue that if we stop the money flow, Cairo will turn to Saudi Arabia or Russia or various Gulf states. But considering how little we get for what we spend, does it really matter?
If those other countries saw much to gain from taking our place, they could have outbid us long ago. Taking on a bigger role, they may find the recipient to be a model of ingratitude, just as we did.
Nor is an end to U.S. aid likely to affect the longstanding peace treaty between Egypt and Israel. Egypt, with all its other problems, needs a war with Israel like the Sahara needs more sand. Israel, for its part, is quite happy to see the generals back in power. The peace accords will survive without us.
Maybe ending aid to Cairo won't work any better than providing it. But at least we'll have a billion and a half reasons not to care.