From the moment 10 years ago that then-President George W. Bush vowed to bring Osama bin Laden to justice “dead or alive,” U.S military forces relentlessly pursued the world's most wanted and elusive terrorist.
Their zeal never changed, nor did their suspicion that bin Laden was seeking safe haven in Pakistan. But their tactics and mindset did – especially after President Barack Obama took office.
The United States had its first opportunity to capture or kill Obama just a few short months after the Sept. 11, 2001 attacks he masterminded. But a poorly organized military assault on a suspected compound at Tora Bora allowed the al-Qaida leader to slither away through unguarded borders.
The initial efforts to capture or kill bin Laden focused on brute force and speed. Large military assaults, missiles shot from unmanned predator drones and other military actions repeatedly missed their mark, as the U.S. casualties mounted -- first in Afghanistan and then in Iraq, which became al-Qaida's new battlefield for foreign fighters.
Bin Laden continued to antagonize, issuing audio and videotapes showing he was alive and spewing his hatred for the West.
Though never the operational and tactical leader, the Saudi-born milionaire was the inspiration for al-Qaida, and his brazen escape from a relentless U.S. pursuit inspired an entire generation of young and radicalized followers.
The longer he survived, the more of a legend he became. And U.S. officials, ever pressing to capture or kill bin Laden, became increasingly disillusioned by their lack of success.
Finger-pointing scarred the military and intelligence arms of the counter-terrorism effort. And U.S. officials openly questioned Pakistan's commitment to capturing bin Laden, while privately whispering their suspicions that Pakistani intelligence may be harboring the terrorist leader or tipping him off to the U.S. pursuit.
Midway through the Bush administration, U.S. officials began to adjust their thinking. The Pentagon's Joint Special Operations Command — home to Navy SEALs, Army Rangers, and other special commandos — became increasingly important to the cat-and-mouse hunt. Not only did they have the military's latest and greatest technology, they also had the mindset to use human intelligence to pursue a target, just like an FBI agent trying to roll up mobsters.
The CIA, through a tenuous agreement with Pakistan, was given the blessing to fire missiles from drones into Pakistan when U.S. officials located high-value targets.
And U.S. officials realized that securing the prize of bin Laden's head would require working more closely with Pakistan to develop realtime intelligence of his whereabouts, despite the distrust the CIA and Pentagon held for that country's intelligence services.
The transition between presidents did little to deter the evolving strategy. Obama told new CIA director Leon Panetta to make getting bin Laden a top priority. Efforts to rely on Pakistani intelligence began to bear fruit, leading to the killings and capture of many top Taliban and al-Qaida leaders in recent months.
A key piece of that puzzle was identifying a man believed to be bin Laden's courier, a trusted aide whose visits to the compound were deemed evidence that the al Qaida leader might be holed up there.
Drone missile assaults on caravans and compounds inside Pakistan grew, along with resentment among some Pakistanis.
And the special forces prized by JSOC were ready on a moment's notice to deploy with precision to kill or capture America's most wanted man.
What started in the early Bush years as an emotional, frantic pursuit transformed itself into a more patient, disciplined exercise of piecing intelligence into a big puzzle. Some leads came from captured terrorists, others from electronic intercepts. Crucial information also flowed from the Pakistanis — a point the president highlighted in his national address late Sunday night.
Finally, last August, U.S. officials believed they had enough of a picture. They had narrowed bin Laden's location to an area not far from Islamabad.
For eight months, they built their confidence in the intelligence and planned for a spectacular assault on a compound — described by U.S. officials as more like a mansion — located in Abbottabad, a city of about 100,000 about 100 miles north of Islamabad.
What began with the spectacular crashing of airliners into the twin towers in New York City on a bright September day 10 years ago ended Sunday with a simple “go” order from Obama and a relatively brief firefight led by U.S. commandos.
The first assault in 2001 left 3,000 Americans dead. The military operation Sunday left no U.S. casualties.
Bin Laden not only was killed, his body was recovered by U.S. authorities to ensure his demise could be confirmed for all the world to believe.
The momentus victory in the war on terrorism will have repercussions, good and bad. The highest-profile inspiration for an increasingly decentralized extremist movement is dead, a development certain to drain momentum from an al-Qaida organization that struggled recently to find its voice during the Arab uprisings.
At the same time, Western officials are certain to brace for retaliatory terrorist strikes and the emergence of new leaders to wage mayhem on the civilized world.
The repercussions of a U.S. attack on Pakistani soil — apparently without the knowledge of the country's leadership — also remain to be seen.
But the decade-long pursuit of bin Laden is certain to rank among America's great accomplishments, a testament to its will to seek justice no matter how long it took.
“Today’s achievement is a testament to the greatness of our country and the determination of the American people,” Obama said in announcing bin Laden's death late Sunday night.
“The cause of securing our country is not complete, but tonight we are once again reminded that America can do whatever it is we set our mind to. That is the story of our history."
Likewise, the ingenuity and evolution of the military's pursuit is also likely to influence future missions. The patience shown over eight months as bin Laden's whereabouts was verified and a carefully designed strike executed is certain to become fodder for a new generation of officers at U.S. military schools.
And the acronym of JSOC is likely to be known and appreciated by a larger number of Americans.