In just one year, the Arab and Muslim world has undergone a total transformation. America's main nemesis since 9/11 is suddenly bursting with new political life, new opportunity and a newly defined will of the people.

It started in Tunisia, North Africa a year ago, when a 26-year-old street vendor decided he couldn't take it anymore. faced with constant petty police harassment and no recourse when he complained to the authorities, Mohamed Bouazizi set himself on fire, and with that one act overturned decades of mostly docile popular obedience under the jackboot of Tunisian dictatorship.

Suddenly the whole region was ablaze with the fierce yearning for change: Two-thirds of the Arab and Muslim population is under 25. People are young, educated, wired, connected and they want exactly what they see the rest of the world enjoying: freedom, democracy, dignity, jobs.

After Tunisian dictator Ben-Ali fled, the revolt spread to Egypt, the leader of the Arab world. The people took to Tahrir, or Liberation, Square, and in a remarkable 18 days, forced down one of the region's enduring leaders, a great ally of the United States AND Israel, Hosni Mubarak. I was the only journalist who saw and spoke to Mubarak during his waning days, and I will never forget him telling me directly that he was tired, fed up, and would step down.

That's very different from Libya's Moammar Gadhafi, who was next in line for the wrath of his people. Unlike Mubarak, he was experiencing total dictator-in-denial syndrome. In another exclusive interview, Gadhafi told me his people loved him and would die to protect him. Instead, they lynched him the moment they got their hands on him, after NATO helped the insurgency depose him with support from the air.

Across North Africa and to the heart of the Middle East, dominoes fell all the way to Syria, and after banning the foreign press and killing more than 4,000 Syrian civilians, according to the United Nations, Syrian President Bashar Assad had the gall to claim he was not in charge and not to blame for the bloodshed, in ABC's Barbara Walters' exclusive interview last week. Again,  dictator-dissembling for all the world to see. His neighbor King Abdullah of Jordan told me he had tried to get Assad to have a national dialogue with his people and end the brutal crackdown, but Assad rejected that advice. King Abdullah told me Assad WAS calling the shots.

So what does all this upheaval mean for the region, and for the United States? The big fear has always been whether Islamist parties would emerge strongest and turn the Arab world toward Islamic fundamentalism.

Because the dictators allowed no political space, the only political activity came out of the mosques. Islamist parties like Egypt's Muslim Brotherhood spent decades in grassroots politics and providing social services.

With the first Arab Spring elections now taking place, this experience is now paying off.

In Tunisia a moderate Islamist party won the most votes in October elections, yet they are at pains to insist their Islam is not at odds with democracy. They point to Turkey, where an Islamist party presides over a secular democracy.

In Egypt the Muslim Brotherhood won the biggest block in this  month's parliamentary elections. But a more puritanical Salafist party named Nour came in a strong second.

Nour and other Islamic parties are trying to allay fears at home and in the West. The Brotherhood insists it will not contest the presidential elections, and lately has been seen as more moderate and politically flexible. Its leaders have taken great pains to portray the party as compatible with serial, secular democracy.

In Egypt the big debate is over how much power the ruling military will maintain as the country moves forward.

There and across the Arab world, minorities, such as Christians, are watching the outcomes carefully, and so, of course, are the women. Having fully participated in all the revolutions, they want their rights enshrined in their future constitutions.

Watch "The Year With Katie Couric" Thursday Dec. 15 at 9 p.m. ET