He told his family he was going on a pilgrimage to Mecca.

Instead, the second-year college student packed a vinyl travel bag and left home in Saudi Arabia for a trip that would take him on a smuggling route across the Syrian border and into the heart of the Sunni insurgency in Iraq.

So began the underground life of safe houses, aliases and hit-and-run attacks of another Islamic foot soldier recruited to battle the U.S. military and its Iraqi allies.

The story — recounted to The Associated Press in a rare interview with a captured foreign fighter — is not one of extraordinary daring or singular cunning. It's about one of the anonymous trigger-pullers in alleys or roadsides — in this case, an ordinary history major who became a rank-and-file gunslinger for insurgent commanders.

The journey of Mohammed Abdullah al-Obeid offers a window into how extremist networks manage to replenish their ranks by combing campuses, markets and mosques for those willing to take up arms in Iraq — and now increasingly in Afghanistan. Even with violence in Iraq tailing off, authorities are concerned that the same clandestine channels used to bring the young al-Obeid into Iraq in late 2005 are still in operation and can be expanded at any time.

Iraq's prime minister, Nouri al-Maliki, has opened a feud with Syria over claims that it is harboring plotters connected to twin bombings in August at the foreign and finance ministries that killed nearly 100 people. Maliki also says Syria has failed to clamp down on insurgent pathways over the border.

Some former members of Saddam Hussein's regime and other Sunni allies fled to Syria after the 2003 invasion — eventually setting up insurgent networks that were tolerated by Syria as a way to keep pressure on American forces and Iraq's Shiite leadership.

The number and roles of foreign jihadists in Iraq over the years is still unclear. There is no disagreement that Iraqis comprised the vast majority of the Sunni insurgency, but certainly thousands — and perhaps more — Arabs and others have crossed the long, unguarded tracts over the Syrian border.

This is how al-Obeid says he entered Iraq — walking without a map and looking for the border town of al-Qaim on the desert horizon.

"I had no idea where I was or even when I crossed the border," the 27-year-old said in an interview arranged by Iraqi security officials in Baghdad's protected Green Zone. "I just knew that we would be soon, God willing, fighting Americans."

Al-Obeid was led into the interview in handcuffs and blindfolded. He wore a blue prison jumpsuit and plastic sandals. Security officers in street clothes were present for portions of the hour-long interview, but left the room at other times. It was not clear whether they were listening in or watching al-Obeid, who spoke in Arabic.

"I may be a prisoner, but I am also on a mission," said al-Obeid, who is clean-shaven with close-cropped hair. "If I'm let out, I will fight again."

His tale could not be independently verified, but it was consistent with other claims by the U.S. military and others on the recruitment and movement of foreign fighters into Iraq.

Al-Obeid said he was first approached about joining the Iraq insurgency during his second year at the Imam Mohammad ibn Saud Islamic University in Riyadh. A fellow student began giving him literature and DVDs about Al Qaeda and the battles in Iraq, he said.

Within weeks, al-Obeid was attending meetings with others who claimed they were ready to join other Arab fighters in Iraq. They were then told that it was now or never, al-Obeid said. He never returned to class.

Al-Obeid — the eldest of four brothers and three sisters — said he went home and told his family he was planning to visit the holy city of Mecca. His parents gave him their blessings and some traveling money. Al-Obeid left with a small bag and about 5,000 Saudi rials, or about $1,300.

"I didn't look back. They thought I was going to Mecca, but I took a bus to Bahrain," he said. "A plane ticket was waiting for me there."

Al-Obeid claims that insurgent recruiters in Saudi Arabia paid for the next leg of his trip: flight to Syria via Dubai. He also carried a phone number to call in Damascus.

"The guy who answered identified himself by only his jihadi name, Abu Qa'qa," said al-Obeid. "He told me to get ready to travel the next morning."

His next stop: the Syrian city of Aleppo on the Mediterranean coast. Al-Obeid said he joined a group of about 20 Arab fighters from across the region: Tunisians, Saudis, Yemenis and others. After a few days, he said they were broken into smaller groups and driven close to the Iraqi border and pointed in the direction of al-Qaim.

Again, he had a mobile phone number of his next contact.

Al-Obeid said he was given a fake Iraqi ID with the name Mohammad Abdullah, born July 19, 1980, and was reunited with some of the Arabs from Syria. Others also were there. Within days, they were driven to Rawah, a village in the flood plain of the Euphrates River in Iraq's western desert. It was early 2006 — a time when insurgents virtually owned the territory.

Al-Obeid's group was divided into two groups. One was prepared for suicide attacks and the other was trained on AK-47s and machine guns.

"I did not choose martyrdom. Instead, I wanted to learn to fire guns and fight in the field," he said.

About a month later, they were in driven to a villa in Baghdad. Al-Obeid said he doesn't remember the area, but he described it as a well-tended street with greenery and flowers. It was only a short breather.

The group was then hidden in a minivan and moved to Diyala province, whose capital Baqouba was then the self-declared capital of the Islamic State of Iraq, an Al Qaeda front organization, and a nerve center of the Sunni insurgency. Al-Obeid said he arrived just weeks before a U.S. airstrike killed Abu Musab al-Zarqawi, the founder of Al Qaeda in Iraq.

"It was a time of big battles with Americans," he said. "I was planting IEDs (roadside bombs) and was part of three big firefights. My bomb-making instructor was Afghani. I killed people. I don't know how many, but I definitely killed American soldiers."

The insurgent networks provided him food and clothes and a monthly stipend of 50,000 dinars, about $40. He was given a room with an Iraqi family and fought alongside some of the brothers. He also took notice of one of their sisters, Nesbah.

"The brothers arranged for us to marry. I had no objection," said al-Obied. "But we decided we should not have children because my wife wanted to become a martyr (suicide bomber). Many women were starting to do it then. She wanted to follow. Even her parents encouraged her to do it. So we began making plans for her martyrdom. I was proud of her."

But Nesbah became pregnant early last year, he said. The decision was made to abandon the insurgency and return to Saudi Arabia. For the first time in nearly three years, al-Obeid said he called home.

"I told them everything and that I wanted to come home now," he said. "They said they would make the arrangements."

What al-Obeid didn't know, however, was that Iraqi intelligence agents were listening, too. A few weeks later in early 2008, he was stopped at a checkpoint on the road from Diyala to Baghdad, by Iraqi forces.

"They asked me, `Are you the Saudi?"' he said. "For me, it was over."

Al-Obeid has been held since by Iraqi intelligence officials. He made no claims of torture or abuses against Iraqi authorities, but it appears al-Obeid could be among the detainees who have agreed to assist Iraqi forces in exchange for favored treatment.

Iraq is currently struggling to handle tens of thousands of detainees held in overcrowded prisons and makeshift jails. The crunch will intensify next year when the U.S. military turns over control of its remaining detention facilities to Iraqi authorities under a security pact. Last month, American officials closed its largest detention site, Camp Bucca near the Kuwait border.

Iraqi and American forces have freed many detainees considered no longer a threat or wrongly jailed. No such pass seems likely soon for al-Obeid.

Asked if regrets joining the insurgency, he replied: "No, I'm very happy."

Would you continue fighting if released?

"Definitely."

He then asked for a pen. He took a clean page of a notebook and wrote in cramped Arabic script. He smiled and handed back the paper.

It read: The wise man is his own judge.