The latest military coup in Egypt stops a slide into one abyss but is hardly a guarantee that it will avoid a future one. A better future will depend on the wisdom of the kind of generals who have not proven to be very wise in the past.
The generals led by chief of the armed forces Abdul Fatah al-Sisi deposed President Mohammed Morsi, the man from the Muslim Brotherhood who was elected only a year ago. His election was the best feature of his rule, which had descended into incompetence and creeping authoritarianism.
Mr. Morsi won the election narrowly over a Mubarak-era political leftover, but he soon reinforced fears that the Brotherhood would use its new power to build an Islamist dictatorship. He tried to claim near-absolute powers by decree to force through a draft constitution written by Islamists and boycotted by everyone else.
The result was political polarization, with the opposition and military uniting against the Brotherhood supporters who were Mr. Morsi's last defenders. The millions of Egyptians who took to the streets were also protesting chronic gas and food shortages and a sinking economy. The uprising shows that the worst fate for Islamists can be to take power and thus be accountable for results. Unlike Iran in 1979, Egypt retains enough competing power centers such as a secular business class and judiciary to prevent an Islamist revolution.
Yet a military coup riding mass protests carries its own risks to future stability. One danger is the reaction of the Brotherhood, which is still the strongest single political party. The secretive group renounced armed struggle in the 1970s. But that could change if its leaders conclude that democracy works for everyone except for them.
Adly Mansour, a judge and interim president sworn in Thursday, called the Brotherhood "part of the nation." But at the same time the military closed down pro-Brotherhood TV stations and put out warrants for the arrest of the party's senior leaders. The Brotherhood is unpopular now, but as memories fade it could return to power with a vengeance if Egypt's next rulers are also unable to fix the country's many problems.
A more hopeful sign is that General Sisi gathered prominent opposition and Coptic Christian and Muslim leaders to announce a new "roadmap" for Egypt's future. The roadmap proposes, among other steps, a broadly representative committee to rewrite the constitution and to form a technocratic government.
General Sisi is also promising new elections, albeit without a timetable. Mohamed ElBaradei, a prominent (and anti-American) secular leader, and the hardline Islamic Salafist Nour Party, a rival to the Brotherhood, have publicly backed the military plan.
The generals don't seem eager to govern directly, especially after they mismanaged the transition after Hosni Mubarak's 2011 ouster until Mr. Morsi's election. Civilians were tried in military courts and abused in custody. As crime worsened and the economy stalled, public ire turned against the generals.
It will do so again without more enlightened leadership that focuses on economic revival and a political transition to a system of checks and balances. Any transition government will no doubt seek money and oil from the Gulf states as well as an early deal with the International Monetary Fund to make up for Egypt's rapidly declining currency reserves.
America can also do more than it has. The Obama Administration has been caught trailing events at every turn, supporting Mr. Mubarak before abruptly throwing him over, and then embracing Mr. Morsi despite his authoritarian turn.
President Obama stayed quiet throughout the latest crisis, finally issuing an anodyne call Wednesday night for "a democratic political order with participation from all sides and all political parties—secular and religious, civilian and military."
Mr. Obama also requested a review of U.S. aid to Egypt, but cutting that off now would be a mistake. Unpopular as America is in Egypt, $1.3 billion in annual military aid buys access with the generals. U.S. support for Cairo is written into the Camp David peace accords with Israel. Washington can also do more to help Egypt gain access to markets, international loans and investment capital. The U.S. now has a second chance to use its leverage to shape a better outcome.
Egyptians would be lucky if their new ruling generals turn out to be in the mold of Chile's Augusto Pinochet, who took power amid chaos but hired free-market reformers and midwifed a transition to democracy. If General Sisi merely tries to restore the old Mubarak order, he will eventually suffer Mr. Morsi's fate.