Perhaps Egyptians will one day remember July 3 as the day they found their way back onto a path toward stable democracy, so fervently craved by the excited crowds in Tahrir Square.
Perhaps, too, the failed one-year rule of the Muslim Brotherhood will one day help Arabs resolve their thorniest problem - the conflict between their hunger for secular prosperity and their devotion to Islam. Egypt's broad-based repudiation of the world's largest Islamist organization may help them draw useful lines between government and religion.
For now, such outcomes look fanciful because what happened Wednesday was not democracy. It was the opposite: mob rule, abetted by military coup, to depose a government elected barely a year ago.
Gen. Abdel Fattah al-Sissi, head of Egypt's armed forces, promised a swift democratic reset. The chief of Egypt's top court, Adly Mansour, took over Thursday as interim president. A broad-based group will write a new constitution, replacing the Islamist-flavored one now in place. New elections will eventually follow. All those steps are better than a general taking power, and they allow the diverse opposition to claim a veneer of revolution, not just coup.
But al-Sissi also set about doing some very undemocratic things. He shut down news media outlets he didn't like and arrested Muslim Brotherhood leaders, including the ousted president Mohammed Morsi.
The question now is how democracy can ever take root in such an environment. If elections can be negated so easily, how can contesting factions trust them as a means of peacefully attaining their goals?
Certainly, the Brotherhood, still by far the nation's best-organized political force, is not likely to trust the process again, even if it is allowed to field candidates.
Had the Brotherhood been voted out in the next election, the Arab world would have had a valuable democratic model: a public repudiation of an Islamist government. Instead, the message is that democracy is fine only as long as the military says it is.
The United States cannot control what comes next, but it has a huge stake in the outcome. Just as a peaceful, democratic Egypt would enhance U.S. security and reduce the terrorist threat, a repressive Egypt with an alienated and hostile Islamist force will increase it.
America must cast its lot with democracy, working to ensure that Egypt's next version is as inclusive as possible. President Obama took a strong step in that direction, urging rapid restoration of civilian government, opposing the arrests of Morsi and other leaders, and ordering a review of U.S. policy in light of the coup, which could jeopardize U.S. aid.
Mobs don't make democracy, even when their intentions are good. Elections do. But they're unlikely to have much meaning if the people are barred from voting for candidates they put into office just a year ago.