They probably could still buy a lot of weapons. Saudi Arabia has already promised Egypt it would replace any aid Western governments cut off, and Kuwait and the UAE also support the country's military. Together, they've already pledged a $12 billion aid package to Egypt's generals.
But losing America's support would cost the Egyptian military two critical factors: training and maintenance, which together make up about a third of the value of our aid. Other than simply offering them more helicopters and guns, the U.S. invites Egyptian military officers to come stateside for training and development, which ostensibly helps them do things like fight terrorists in the Sinai peninsula.
We also help them keep their weapons operational: When we give them a new F-16, for example, we also guarantee that Lockheed Martin will help them maintain it.
"If the U.S. company won't provide that service, these things might not one able to fly," said David Schenker, director of the program on Arab politics at the Washington Institute for Near East Policy.
2) Would Egypt stop preserving American interests in the Middle East?
In exchange for the aid, we count on Egypt to fight jihadists in the Sinai, serve as a buffer to Iran's growing power, and to let us fly over their territory and use the Suez Canal whenever we want.
But those things aren't just in America's interest, they're in Egypt's, too.
As Kaplan writes in Slate, "The Egyptians do not want to incite a war, or an arms race, with Israel. They don't want terrorists roaming free in their northern territories. They fear and loathe the prospect of Iranian expansion."
Furthermore, Schenker argues that Egypt's power to preserve stability in the region is exaggerated. The country recently squabbled with Ethiopia over a plan to dam up the Nile, a sign for Schenker that Egypt doesn't call the shots like it once did.
"We can't really count on these guys to face off against Iran when they can't even intimidate Ethiopia into giving them all the Nile water they want," he said. "Their stature has declined."
Robert Springborg, an expert on the Egyptian military at the Naval Postgraduate School in Monterey, Calif., says the military's failure to control terrorist threats in the Sinai shows that even with American aid, it can't adequately keep the peace within its own borders.
"Over time, the 'paper tiger' nature of the Egyptian military will be its undoing," he said. "As the Egyptians realize they have paid a huge price for a military that is not only not under their control, but cannot do its job either."
3) Would the Egyptian security forces stop cracking down on the opposition?
This one is tough to predict, but it's doubtful. Though the military has historically suppressed the Muslim Brotherhood, this time they seem bent on totally destroying the group's presence in the country.