Borrowing a concept from mathematics, David Ignatius calls what we're seeing in the Middle East these days "a glorious catastrophe," but warns that now is not the time for triumphalism:

It's hard not to feel giddy, watching the dominoes fall. In Lebanon, "people power" forced the resignation Monday of Syria's puppet government; in Egypt, the Pharaonic Hosni Mubarak agreed Saturday to allow other candidates to challenge his presidency for life; in Iraq, the momentum of January's elections is still propelling the nation forward, despite bickering politicians and brutal suicide bombers.

But catastrophic change is dangerous, even when it's bringing down a system people detest. This is not a time for U.S. triumphalism, or for gloating and lecturing to the Arabs. That kind of arrogance got us into trouble in Iraq during the first year of occupation. It was only when Iraqis began to take control of their own destinies that this project began to go right. The same rule holds for Lebanon, Egypt and the rest. America can help by keeping on the pressure, but it's their revolution.

That's good advice. Let's hope that the folks in charge, as well as some of their more, uh, excitable supporters, can bring themselves to take it.