Washington - A glimpse of the passionate loyalty inspired by Abu Bakr al-Baghdadi, the leader of the insurgent group known as the Islamic State of Iraq and Syria, comes in a recent video made by a 20-year-old Muslim recruit from the British city of Cardiff, Wales.

"We understand no borders," says the young man, identified as Nasser Muthana, a recruit who apparently joined ISIS about eight months ago. "We have participated in battles in [Syria] and in a few days we will go to Iraq and will fight them, and will even go to Lebanon and Jordan, wherever our sheik [Baghdadi] wants to send us."

"Send us, we are your sharp arrows. Throw us at your enemies, wherever they may be," pledges the young man to Baghdadi on the video. The British recruit is dressed in a simple uniform and a light head scarf, his thin beard a sign that he is barely out of high school. Before he decided to join the jihad, Muthana, whose family emigrated from Yemen to Britain, had been accepted by four medical schools in Britain, according to an analysis by the Daily Mail.

Baghdadi's ability to inspire such intense support worries U.S. officials. His fighters seemingly will go anywhere and do anything for the cause. They combine a fanatical passion with an unusual degree of organization, technical skill and tactical planning.

"Baghdadi is a ruthless, resilient and ambitious terrorist leader who unfortunately has shown a knack for tactical operations and, it seems, military strategy," says a U.S. counterterrorism official. He describes Baghdadi as "headstrong" and "opportunistic" in his ability to break with core al-Qaeda leadership and fashion alliances with Iraqi and Syrian tribal leaders.

Baghdadi may be more skillful in the field than either of his mentors, Osama bin Laden or Abu Musab al-Zarqawi, the leader of al-Qaeda in Iraq. He is creating his own "emirate," guarded by tanks and heavy weapons, something bin Laden only dreamed of. And he has recruited Sunni tribal leaders with more finesse than Zarqawi, whose hyper-violent tactics ultimately turned the Iraqi population away from him.

"Baghdadi is the unquestioned leader of [ISIS] and relies on a set of trusted lieutenants, but he has empowered local commanders to make decisions and seems to have employed a somewhat decentralized command structure," says the U.S. counterterrorism official. It's a mob-like approach, with Baghdadi using "brutal methods to terrorize civilian populations" and financing operations with "coercive methods that would be familiar to an organized crime group," the official explains.

Baghdadi's gang-leader charisma may reflect the time he spent as a prisoner at Camp Bucca, a U.S.-run detention facility that U.S. military officers feared was becoming a school for jihadists. The likelihood these camps were radicalizing inmates was "a very real concern," Maj. Gen. Douglas Stone, then deputy commander for detainee operations, told Newsweek in 2007.

It's telling that as Baghdadi has built his organization over the last several years, one of his most effective tactics has been to liberate Iraqi prisons that were holding al-Qaeda detainees. ISIS mounted a sophisticated attack on Abu Ghraib and Taji prisons nearly a year ago, which freed up to 1,000 inmates, many of them hardened al-Qaeda fighters. An Iraqi government communique noted then how sophisticated the attack was, combining car bombs, suicide bombers and coordinated mortar fire. When ISIS swept through Mosul this month, the group freed another 2,000 to 3,000 veteran fighters from a prison outside the town.

Though the U.S. official describes Baghdadi as a "home-grown terrorist" who has never traveled outside Iraq and Syria, his group has cleverly mobilized international social media to boost its cause. The online journal War on the Rocks this week analyzed a "Twitter storm" on #AllEyesOnISIS. In a 24-hour period that began last Friday, there were 31,500 tweets, with the top 50 tweeters accounting for nearly 20 percent of the volume, or an average of 126 messages per person.

"This shows that a small number of enthusiastic and deeply invested activists shouldered the burden," the journal noted.

Baghdadi's semi-official biography, disseminated on jihadist websites, stresses his piety and family values. His father is a tribal elder who "loves the religion." His grandfather was known for persistent prayer, and "being good to his kin, and keenness to the needs of the modest families." Though Baghdadi rarely speaks in public, he has "an eloquent speech and strong language and has an obvious acumen and smartness."

The ISIS leader, in sum, is a clever, disciplined, violent and charismatic man - with an eye for manipulating Muslim public opinion.

(c) 2014, Washington Post Writers Group