As U.S. helicopters secretly entered Pakistani airspace Sunday, the Joint Operations Center at Bagram Airfield in Afghanistan was under the control of a square-jawed admiral from Texas who had labored for years to find Osama bin Laden’s elusive trail.

Vice Adm. William H. McRaven, one of the most experienced terrorist hunters in the U.S. government, had tapped a special unit of Navy SEALs for the mission two months earlier. A former SEAL himself, McRaven had overseen weeks of intensive training for a covert operation that could cripple al-Qaeda if it worked, or strain an already troubled alliance with Pakistan if it went awry.

The search for bin Laden was led by the CIA, which painstakingly pieced together scraps of intelligence that eventually pointed to a high-walled compound in Abbottabad, Pakistan. But when President Obama gave the authorization to invade the site, CIA Director Leon Panetta delegated the raid to McRaven, who had been preparing for such a moment for most of his career.

He has worked almost exclusively on counterterrorism operations and strategy since 2001, when as a Navy captain he was assigned to the White House shortly after the Sept. 11 attacks. The author of a textbook titled “Spec Ops,” McRaven had long emphasized six key requirements for any successful mission: surprise, speed, security, simplicity, purpose and repetition.

For the especially risky bin Laden operation, he insisted on another: precision.

Vice Adm.William H. McRaven’s forces have killed or captured hundreds of insurgents over the past year, mostly in nighttime raids. (US NAVY)

“He understands the strategic importance of precision,” said a senior Obama administration official who worked closely with McRaven to find bin Laden, speaking on the condition of anonymity because of the sensitivity of the operation. “He demands high standards. That’s why we’ve been so successful.”

As leader of the military’s highly secretive Joint Special Operations Command, McRaven has overseen a rapid escalation of manhunts for Taliban leaders in Afghanistan and al-Qaeda figures around the world. Although he’s a three-star admiral, the muscular 55-year-old still sometimes accompanies his teams on snatch-and-grab missions.

On Friday, McRaven received the green light from Panetta to launch the raid at the earliest opportunity. Later that day, he met with a six-member congressional delegation that was coincidentally visiting Afghanistan. He gave the lawmakers a tour of the Bagram operations center that — unbeknownst to them — was gearing up for the critical mission.

“Little did we know he had already given the order to take out Osama bin Laden,” said Rep. Bill Shuster (R-Pa.), who led the delegation.

McRaven had been just weeks away from leaving Afghanistan for a new assignment. He had led the Joint Special Operations Command since 2008, when he succeeded Army Gen. Stanley A. McChrystal, whose team helped turn the tide of the war in Iraq by relentlessly targeting insurgent leaders, including al-Qaeda’s chief in Iraq, Abu Musab al-Zarqawi. Zarqawi was killed by a U.S. airstrike in 2006.

“Nobody thought it would be possible, frankly, to take that command beyond what Stan McChrystal did, but he has,” said Michael G. Vickers, undersecretary of defense for intelligence. “He has taken what was already a very integrated, interagency organization and taken it to another level.”

Vickers has known McRaven since he was a Navy SEAL lieutenant commander and Vickers an Army Special Forces captain. They’ve worked especially closely over the past four years, when Vickers served as the Pentagon’s top civilian official overseeing Special Operations forces, including units hunting al-Qaeda and Taliban leaders.

“Bill is a great leader but also a pretty big thinker,” Vickers said. “It’s a rare balance of these two skills.”

McRaven returned to Washington after bin Laden’s death and briefed lawmakers in a closed session Wednesday on Capitol Hill. He declined to be interviewed for this article.

He grew up as the son of an Air Force colonel who flew British Spitfires during World War II and played briefly in the NFL. McRaven graduated from the University of Texas at Austin, where he studied journalism, in 1977. His 1995 book analyzed eight famous moments in special-operations history, including the Israeli raid to free hostages on a hijacked airliner at Entebbe, Uganda.

Unlike some high-ranking military officers, McRaven is “definitely not a yeller-screamer,” said a former Special Operations official who has known him for years and spoke on the condition of anonymity because of the clandestine nature of their work. “He’s a guy that I think you can look at as a modern-day SEAL, a post-Vietnam-era SEAL — guys that are quiet, humble, smart.”

Under his leadership, the Joint Special Operations Command has expanded its reach beyond Afghanistan and Iraq. In September 2009, McRaven negotiated an agreement with Yemeni President Ali Abdullah Saleh to conduct secret missions with Yemeni troops against al-Qaeda in the Arabian Peninsula, an affiliate of bin Laden’s network that some officials say has become the primary terrorist threat to the United States.

But McRaven has spent most of his time in Afghanistan, where JSOC efforts have greatly intensified. His forces have killed or captured hundreds of insurgent leaders over the past year, primarily in nighttime raids, according to U.S. military officials.

They have portrayed the raids as a cornerstone of their war strategy. Although they acknowledge that such raids alone cannot defeat the Taliban, “the results have been staggering,” said the senior Obama administration official.

But the nighttime operations have strained relations with the Afghan government, which says that the raids often target the wrong individuals and that U.S. forces are not held accountable for lethal mistakes.

In October, Special Operations forces accidentally killed a kidnapped British aid worker with a grenade during a botched mission. U.S. officials at first blamed the death on the Taliban but were forced to retract the assertion.

Also last year, after Special Operations forces killed five innocent Afghan civilians in another bungled raid, McRaven admitted that his team had committed “a terrible mistake” and visited the victims’ relatives to ask for forgiveness.

Paying homage to tribal honor codes, McRaven took two sheep to the village in Paktia province and offered to sacrifice them in a mercy-seeking gesture. Village elders spared the sheep but did accept a cash payment of about $30,000, according to an eyewitness account reported by the Times of London.

“I am a soldier,” McRaven told the father of two of the victims. “I have spent most of my career overseas, away from my family, but I have children as well, and my heart grieves for you.”

In an attempt to minimize further casualties, McRaven ordered the reinstallation of bright-white spotlights on AC-130 gunships that often accompany assault forces on the nighttime raids. Military officials describe the lights as an intimidating factor that encourages insurgents to give up, or at least not to flee and grab a weapon.

In March, Defense Secretary Robert M. Gates said he was recommending McRaven for promotion to four-star admiral and leader of the U.S. Special Operations Command, based in Tampa.

The move is subject to Senate approval. But Shuster, the congressman, said that given McRaven’s role in bin Laden’s capture, “they won’t be able to confirm him quickly enough.”

Staff writers Greg Miller, Dana Priest and Karen Tumulty and staff researcher Julie Tate contributed to this report.