He was for years Libya's greatest hope for a peaceful, orderly transition away from his erratic father's autocratic rule. As such, the seemingly open-minded son of Col. Moammar Kadafi was feted by world leaders and greeted with approval by international human rights groups and even some opposition activists as a beacon of reform in a politically ossified North Africa.
Now Seif Islam Kadafi, 38, is hunkered down in a besieged capital, shorn of his reformist mantle and taking a front-and-center role in organizing his family's defiant attempt to survive a revolt that has left rebels in control of large swaths of the desert nation.
With hundreds dead, tens of thousands scurrying to safety abroad, and the onetime reformer having warned that his father's security forces would fight "to the last bullet" in streets that would "run with blood," Seif Islam acknowledges that any vision of top-down change has come off the rails.
"Everybody in Libya knows that there was a big plan to implement reforms on March 2, the opening of parliament," he said in an interview Monday night in a luxurious office used by Libya's prime minister. "We wanted to start a drastic change: new laws, constitution, local governance. But because of the event it's hard to focus on reforms, because our main goal is security and peace."
Critics of the Libyan regime counter that the younger Kadafi's reform agenda was always a facade, a way of cozying up to the West when Libya needed expertise and investment from abroad.
"Just the mask came off," said Riad Kahwaji, chief executive of the Institute for Near East and Gulf Military Analysis, a think tank with offices in Beirut and Dubai, United Arab Emirates. "This is the real him. The reformist talk … he was just trying to speak what appeases the West just to pave his way into succeeding his father."
Whatever the motivations, Seif Islam has stunned his erstwhile sympathizers by taking to the airwaves and warning of civil war if protests continue. Video has emerged showing him brandishing a weapon as he addressed a crowd of militiamen.
"You will receive all the support … and the arms," he said in the clip, posted on YouTube. "Everything will be OK."
Seif Islam's tone has softened significantly since the government has appeared to consolidate its control over Tripoli, the capital. On Friday, at his behest, dozens of international journalists began entering the country, part of an effort to counter what government supporters describe as a conspiracy to undermine Libya.
"This is all part of a well-organized campaign against Libya," he said in the interview. "Everything happened here because of the foreign media. That's why I want you to come and see and go and tell people what's going on here. What's on the ground is different."
Libya's unrest, after successful revolutions in neighboring Tunisia and Egypt, has caused the Kadafi family, he said, to close ranks around its patriarch, who has ruled the country for 41 years.
"All of us, we are not happy," Seif Islam said of his father and family. "It's a big challenge for everyone."
Seif Islam insisted, however, that his views on opening Libya's political system haven't changed. He says he will continue to push for liberalized treatment of the news media and civil society groups, more political freedom, a new penal code, expansion of local government and a new constitution.
"We made a decision to go forward," he said. "The only problem now, first, is to restore law and order."
Some outsiders who have worked with Seif Islam in previous efforts to loosen Libya's political system say he may be a man caught between his Western-oriented education and outlook, and the demands of his unbending father.
"When you're applying for a job, sometimes your potential employer puts you under pressure to see how you react," said Lahcen Achy, a North Africa specialist at the Carnegie Endowment for International Peace. "The guy is reacting under pressure. We've seen a completely different person."
Tall, gaunt and articulate, Seif Islam studied architecture in Tripoli, business in Vienna and received a doctorate from the London School of Economics on the topic of democracy and civil society.
On his return to Libya, to work as an architect and pursue charitable work, he reached out to Libyan opposition groups abroad, international human rights groups and even Islamic militants who had vowed to kill his father. He met in November 2008 with U.S. Secretary of State Condoleezza Rice during a high-profile visit to Washington.
"He did concrete things." said Sarah Leah Whitson, Middle East and North Africa director for Human Rights Watch, which was allowed to hold a news conference in Libya thanks to Seif Islam's efforts. "There was a real reform effort."
Many within Libya's security establishment resisted. The Human Rights Watch news conference devolved into a chaotic shouting match when participants alleging government abuse were attacked by men who appeared to be security officials.
Some speculate that another of Kadafi's sons, Mutassim, who serves as a security advisor to his father, has been locked in a succession battle with Seif Islam. Whitson said she believed that the reform program was squashed or scaled back months before the uprising.
"My theory is that there was a tug of war," Whitson said. "There was a showdown. [Seif Islam] lost the battle."
Without question, his reaction to the uprising has cost Seif Islam his reputation as an enlightened thinker and his ties to the London School of Economics, which has received funding from a charity he founded.
"Rather than seeing the opportunity for reform based on liberal democratic values and human rights, [Seif Islam] stressed the threat of civil war and foreign intervention," David Held, one of his mentors at the school, said after Seif Islam's harsh Feb. 20 remarks, which prompted protests against the $2.4-million donation the school had received from the Gaddafi Foundation for researching good governance in North Africa.
Held described Seif Islam as "a young man who was caught between loyalties to his family and a desire to reform" Libya.
"He tragically, but fatefully, made the wrong judgement," Held wrote in a statement announcing that the school would end its ties to the Kadafis.
The university announced Tuesday that it was also investigating claims that Seif Islam had plagiarized parts of his doctoral thesis.
Seif Islam says his nation has been unfairly stigmatized by the international community and sanctioned by the United Nations because of exaggerated news reports about the unrest, including what he described as unproven allegations that the Libyan air force has launched airstrikes against protesters.
"For the first time in the history of modern diplomacy, the United Nations Security Council issued a resolution … based on wrong media reports," he said.
Although he acknowledged that hundreds have been killed in the unrest that began in mid-February, he dismissed the notion that Libya's troubles stem from the same youthful clamoring for changes that unseated neighboring governments, which were afflicted with problems he said Libya has solved. That's a contention he might have laughed off a few years earlier, when he prescribed political change across the Arab world.
"In Tunisia, you had a big violation of human rights, big oppression and corruption," he said. "In Libya, we freed all the prisoners, no violation of human rights, no torture anymore, no corruption as a family. In Egypt and Tunisia, the whole nation stood up and moved against the government. Here it's the other way around."
The younger Kadafi insisted that he doesn't intend to take up his father's post. "I have no ambition to become the president," he said.
But the nature of Kadafi's rule, his demands for fealty, may have forced Seif Islam to choose between making reforms and serving as a standard-bearer for his family. "Seif Islam could have played a mediator role if he had correctly read the situation in Libya from the beginning and put some distance from his father," the Carnegie Endowment's Achy said. "But this would have been very difficult because Kadafi is not tolerant."
Special correspondent Alexandra Sandels in Beirut and Times staff writer Henry Chu in London contributed to this report.