“When I turned 40, I had come into contact with other adoptees who had been adopted to France,” Mr. Drennan said. “We started talking back and forth, and they were the ones who got me thinking about the politics and economics of adoption.”

Mr. Drennan began a process of critically evaluating adoption, seeing it as a way that wealthier families, and wealthier parts of the world, absorb the children of families whose poverty they have a role in causing. When he looked at the name on his birth certificate, he had a disturbing revelation. His name and place of birth had been invented — by well-meaning nuns.

“I realized in the paperwork, the name was fictitious,” Mr. Drennan said. “It was given to us by the orphanage. I went into a tailspin. I once had a friend’s father translate the papers for me, and he said, ‘These are all from different offices within the government, from the parish priest, but it’s all the same handwriting.’ It had the legality of it, but the nuns had done it all.”

“That got me thinking, ‘I want to go back, I need to go back,’ ” Mr. Drennan said.

At first he thought of taking just a summer course in Arabic. But when he saw a posting for an instructorship of graphic design at the American University of Beirut, he applied and got the job. In 2004, he moved back to Lebanon.

At first, he said, living in the land of his birth family was “overwhelming” at times. “Because of the way Lebanese culture works, at any given time, I can be three, four, maybe five steps away from my family,” he said. “When I first got there, I would focus on facial features, or hair patterns, or the shape of their hands.”