CHESTERTOWN, Md. – Shiraz Maher went to the mosque in search of answers.

Why, he wanted to know, had 15 young men from Saudi Arabia, the country where he spent most of his childhood, just crashed jetliners into prominent U.S. buildings?

The men who gave him clarity wore fashionably tailored suits and spoke as easily of Shakespeare and Hegel as they did of the Quran. The 20-year-old Briton found these Muslims — as urbane as they were devout — alluring.

By the time U.S. forces invaded Afghanistan three weeks later, Maher was a recruit of Hizb ut-Tahrir, or Party of Liberation, an organization devoted to creating a pan-Islamic state ruled by religious law.

“America, in my mind, had gone to war with Islam,” says Maher, now 30.

The story of Maher’s last decade speaks to a question that has perplexed Americans since the attacks of Sept. 11, 2001. Why do some young Muslim men, even well-educated ones from the middle class, come to see us as the enemy? It’s an issue to which Maher, teaching at Washington College this semester, brings firsthand perspective.

Washington College President Mitchell Reiss was visiting London for a debate on terrorism when he heard Maher’s story of entering and ultimately leaving Hizb ut-Tahrir. “It demonstrates how a highly intelligent, well-educated individual can be seduced to go down an incredibly dangerous path,” Reiss says.

As a result of their meeting, the former jihadist has spent this spring teaching in Chestertown. He has led a class on Middle Eastern politics and recently delivered a lecture on his personal story to a rapt audience of students and townspeople.

Maher is a senior research fellow at the International Centre for the Study of Radicalisation at King’s College London. He has also reported on the Middle East — witnessing the uprisings in Egypt, embedding with the Pakistani army and visiting a deradicalization center in Saudi Arabia — for British news media.

Maher was born in Birmingham, England, to a family of Pakistani origin. When Maher was a few months old, the family moved to Saudi Arabia, where his father worked as an accountant for a member of the royal family.

Maher grew up in a large expatriate compound where every house had a swimming pool. His father was a secular Muslim in a country where all activity stopped for daily prayers.

“The image people got of Saudi Arabia after 9/11, as some kind of Taliban state, just isn’t correct,” Maher says. “I had a great childhood.”

He returned to England as a teen to live with his grandparents and study history. He would have described himself as an atheist or agnostic at the time.

But he had acquired in Saudi Arabia a general sense that the United States interfered too frequently with the affairs of Muslim countries. He remembers wearing a T-shirt when he was in grade school that proclaimed “I Support Operation Desert Storm.” The disgusted looks of classmates told him his pro-U.S. sentiment was out of step.

So, when the planes tore into American buildings on Sept. 11, Maher was not exactly outraged at the attackers. “My reaction was not, ‘This is great,’ ” he says. “But I saw it as blowback, like the Americans had gotten their comeuppance.”

What really struck him, as details emerged, was that so many of the hijackers hailed from Saudi Arabia.

His thoughts pushed him to a local mosque, where he met the members of Hizb ut-Tahrir who so impressed him. “What do you think about what happened?” they asked him. Maher said that maybe the U.S. had invited attacks.

“This is irrelevant now,” he remembers one of the men saying. “Whether it was justified or a crime doesn’t matter. What matters is that the U.S. is going to use this as a pretense to wage war on Islam.”

Given that framing, he decided he’d rather throw his lot with the world’s 1.5 billion Muslims than with the United States. He now regards his thinking as wildly idealistic.

Hizb ut-Tahrir did not directly advocate violence. Maher says his mentors regarded al-Qaida as well-meaning but ill-conceived in its methods. He describes Hizb ut-Tahrir as “the political wing of global jihad,” devoted to radicalizing the thinking of Muslims but not to producing fighters.

Bill Braniff, executive director for the START consortium on the study of terrorism at the University of Maryland, College Park, says Hizb ut-Tahrir operates in a gray area by advocating the overthrow of governments but not directly inciting or funding violence. “It’s certainly a difficult question for national security professionals,” he says of dealing with such groups, “because they could be aiding in radicalization but are still operating carefully under constitutional protections.”

Almost overnight, Maher broke up with his girlfriend, swore off alcohol and began a rigid prayer schedule.

Maher says he rose quickly in Hizb ut-Tahrir, assuming a supervisory role of multiple training cells in Northern England. Success fed his ego. “I was 21, and there were 40-year-olds listening to me with military precision,” he recalls.

Hizb ut-Tahrir operates all over the world, but its English branch worked on a few specific goals, Maher says. Members raised money to send to countries such as Pakistan and Egypt, where rebellion against secular governments seemed possible.

Maher moved to Cambridge to continue his studies in 2004 and began a deeper examination of Islamic political thought that revealed cracks in the group’s ideology. But that did not make the decision to leave Hizb ut-Tahrir an easy one.

His closest friends were radical Islamists, and he knew those relationships would end the moment he stepped away. He was used to sleeping soundly with the certainty that his fate lay in God’s hands. That assurance, too, would disappear.

When terrorist bombs rocked London’s transit system on July 7, 2005, killing 52 people, Maher could wait no longer. He couldn’t stand to feel culpable, even tangentially, for such violence. After seven months of agonizing, he left.

In his work and his teaching, Maher emphasizes the complexity that he ran away from as a radical activist. No conflict is as simple as West vs. East or Muslim vs. Christian, he tells his students. There are matters of climate, economic class and ethnic heritage that complicate every struggle.

Maher wasn’t sure how to broach his past at Washington College. He finally showed his students a video he made for the British Broadcasting Corp. about his time in Hizb ut-Tahrir. Ultimately, they say, his experience added to his teaching.

“It struck me as remarkable,” Richard Niroumand, a junior from England, says, “that he could totally abandon his actively jihadist lifestyle and transform into an outspoken advocate of democracy and a levelheaded critic of jihadist organizations.”