This Arab Autumn may be as instructive as the Arab Spring. On Tuesday, the 11th anniversary of 9/11, Americans got a reminder that terrorist acts by Islamic extremists against the U.S. aren’t in our rearview mirror. They’re just awaiting the right moment to take center stage again.

That right moment came this week with the killings of four Americans, including U.S. ambassador to Libya Christopher Stevens, in an outburst of anti-American violence and protests that lit up Libya and Egypt. It was sparked or (in the case of Libya) inflamed by a provocative, amateurish American film that mocks and denigrates the prophet Muhammad.

The protests have punctured the euphoric fantasy many Americans have held of the Arab Spring, those Middle East uprisings two years ago that toppled long-serving despots. Extremists on Tuesday showed that the hatred against the West has not gone away, and that democracy is having a difficult time finding traction.

Those realities underscore the challenges the U.S. faces.

Yet, things have changed in the region. Nowhere was that more clear than in the reaction of most Libyans to the assault and deaths at the U.S. consulate in Benghazi.

Several Libyan security guards were reportedly hurt or killed trying to protect the Americans. Libyan guards jumped into the smoke-filled building to pull Stevens out and drive him to a hospital where staff unsuccessfully tried to revive him.

Top Libyan officials quickly condemned the deadly attack, offering heartfelt apologies and vowing to help find the killers. (On Thursday, officials said an unspecified number of militants have been arrested.) Newly elected Libyan prime minister Dr. Mustafa Abushagur was blunt in his response: “I condemn these barbaric acts… This is an attack on America, Libya and free people everywhere.”

And Libyans have flooded Facebook with words of support for the U.S., and have taken to the streets in counter-protest armed with signs saying “Benghazi is against terrorism” and “Chris Stevens was a friend to all Libyans.”

Libyans’ support, and that of others in a region that has been rife with anti-American sentiment for years, is a change worth remembering as lawmakers and pundits urge punitive policy changes against both Libya and Egypt. Some on Wednesday were already calling for the U.S. to suspend financial aid and security cooperation to the two countries.

But GOP U.S. Sen. John McCain, who gave an impassioned tribute to Stevens on the Senate floor on Wednesday, had the right advice: “We were right to take the side of the Libyan people, and others in the region who share their peaceful aspirations. And we would be gravely mistaken to walk away from them now. To do so would only be a betrayal of everything that Chris Stevens and his colleagues believed in… it would also be a betrayal of America’s highest values and our own enduring national interest in supporting people in the Middle East who want to live in peace and freedom.”

His words echoed those of President Obama. He vowed “justice will be done” in punishing the perpetrators but also noted that the attack won’t “break the bonds between the United States and Libya.”

It’s shameful that the tragic events have been overshadowed by blatant politicking. GOP presidential candidate Mitt Romney’s rushed statement condemning Obama’s handling of the crisis has been widely repudiated, even by some Republicans, for being inaccurate and inappropriate in the heat of an international crisis. Would that he’d had the restraint his wife Ann showed in answering a question Charlotte’s WCNC-TV anchor Dave Wagner posed to her Wednesday about the events in Libya. Her response: “Right now, the appropriate emotion should be … sorrow for those that have fallen.”

She’s right, as is the Obama administration in sending warships and Marines to the area to beef up security for foreign service workers in the volatile Mideast, and in pledging to continue to support and work with Arab leaders on democratic reforms and an end to terrorist activity.

This 9/11 tragedy highlights once again that the fight against terrorism and extremism will be long. The Arab Spring was a hopeful sign that progress can result. But we must work for that progress – and work with countries still battling hard.