WASHINGTON ― After weeks of exhilarating scenes from Tahrir Square, Egypt offered a reality check that shows how hard the transition to democracy will be in the Arab world: The essential ingredient will be a culture of tolerance ― and a spirit of unity that overcomes political, religious and other differences. 

The ugly old politics of division surfaced last week in Egypt in three dramatic confrontations: Participants in a women’s march reportedly were “groped” by male bystanders; Coptic Christians clashed with Muslims following the burning of a church, leaving 13 dead; and protesters ransacked the files of the hated security police, looking for dirt on the old regime, and perhaps on their neighbors.

What a democratic culture does is take these real and inescapable tensions and find a constructive outlet for them. The Arabic chant “Salmiya” ― peaceful ― was one of the unifying themes of Tahrir Square, and it’s needed now just as much in the post-Hosni Mubarak era. The Tahrir movement was made up of disparate groups ― socialists and capitalists, men and women, Muslims and Christians ― but they found a common language. I hope they don’t get amnesia.

The danger is that the nascent democracy will turn into anarchic discord, followed by renewed repression ― a process all too common in post-revolutionary history. The idealism of the French Revolution gave way to the bloodletting of the Committee of Public Safety, which in turn brought the crackdown known as Thermidor. The young democrats of Egypt, Tunisia and Libya will avoid this tragic cycle only if they embrace tolerance.

Let’s take the example of the security institutions of a new Egypt. The police became the enemy for the Tahrir Square protesters, and there’s still a lot of pent-up rage at Mubarak’s repressive state. But Egyptians want law and order, too, and they will need a modern, efficient police force that doesn’t harass or torture people. They will need an effective intelligence service, too, for that matter.

How to help the Arabs build modern security services? After the fall of communism, the United States assisted the nations of Eastern Europe in establishing such organizations, with appropriate rules and oversight. America is not the right country to help reconstruct the new Egyptian security service (we were too involved in the evils of the old one), but how about a mission from Poland, or the Czech Republic, or other nations that created police and intelligence agencies on a democratic model?

American history is about the gradual development of such a culture of tolerance, and it took us decades to get it right. We revere the Founding Fathers, but Washington, Adams, Jefferson, Madison and Hamilton spent the 1790s firing rhetorical spitballs at each other. Our young republic bounced between the anarchic protests of the Whiskey Rebellion and the police-state repression of the Alien and Sedition Acts.

America was lucky to have a Bill of Rights amending its new Constitution, which guaranteed a baseline of tolerance that would make democracy possible. I hope that Egyptians and their neighbors will think about their own versions of such a bill of rights, to guarantee freedom of religion, press and other human rights.

And on the subject of press freedom, it is disheartening to see regimes such as Jordan, which claim to want reform, encourage the suspension of the weekly column in The Jordan Times by Randa Habib, the widely respected Amman bureau chief of Agence France-Presse. Bravo to the 200 brave Jordanians journalists who demonstrated last week for press freedom. If King Abdullah II wants to be seen as a genuine reformer, he needs to embrace this cause rather than fight it.

As the Arab world struggles to create a democratic culture, I hope it will hear more from President Obama. He is a symbol of America’s own progress toward that goal ― and he’s a man with standing to give some advice: an African-American, the son of a Muslim father, a person whose demeanor and governing style convey the reticence and respect for others’ views that make democracy work.

Obama has been criticized for not being more interventionist in his response to the uprisings in Egypt and Libya. Mostly, I think that criticism is bunk; Obama has been right to keep this a narrative written by Arabs, without American meddling. But on the subject of creating new and tolerant democracies, Obama should find his voice. Isn’t it time for a new Cairo speech that aligns America with this process of change? 

By David Ignatius

David Ignatius’ e-mail address is davidignatius@washpost.com ― Ed.

(Washington Post Writers Group)