The Taliban has regained legitimacy in Afghanistan and Pakistan, journalist Ahmed Rashid said yesterday in a lecture at the Harvard Kennedy School.

Rashid, a correspondent for the Far Eastern Economic Review and Britain’s Daily Telegraph who wrote a best-selling book on the Taliban, said that the group has become a regional security problem—not just an Afghani one—and that it is causing instability in much of central Asia.

“The Taliban has become a kind of brand now, not just of extremism but a model of society,” Rashid said.

That “brand” largely moved into tribal areas of Pakistan after the American invasion of Afghanistan in 2001. There, they trained virtually unimpeded until the Pakistani army began to intervene in 2004.

Rashid said the United States’s lack of focus on rebuilding and stabilizing Afghanistan was a major reason the Taliban was able to regain power and gain new recruits.

“How did we get here?” he asked. “In one word, Iraq.”

The solution will not come from solely increasing U.S. military presence in Afghanistan, Rashid said.

The remedy should be a major diplomatic initiative, involving countries such as Iran and India.

These countries are crucial because each has an interest in Afghanistan’s future and many of them seek to control the country now, Rashid said.

“Kabul has become the new Kashmir,” Rashid said, referring to the growing rivalry between Indian and Pakistani intelligence services in Afghanistan’s capital.

Some audience members, including Kurt L. Sonntag, a Kennedy School national security fellow who has spent time in Afghanistan and Pakistan, disagreed with where Rashid placed blame for the Taliban’s rise.

“Some of the premises that the U.S. is at fault are not quite correct,” Sonntag said.

“But there needs to be an international solution, so everything he said bears looking at.”

Timothy F. Krysiek, a Cambridge energy consultant who attended the lecture, found that Rashid’s insight was important but unavailable to the American public.

“It’s such a pressing issue, such a part of our political debate, but you would never get him unplugged for 15 minutes on CNN,” Krysiek said.