U.S. forces launched Operation Enduring Freedom this year in response to the terrorist attacks on New York and Washington that left some 3,000 dead.
Few, if any, of the Pentagon's more than 20,000 workers ever expected the U.S. Defense Department's headquarters would be on the front lines of a war.
But on September 11, suicide hijackers commandeered American Airlines flight 77 from Washington to Los Angeles. They turned it into a deadly terrorist weapon by crashing it into the building. The fuel-laden aircraft cut a swath of destruction through a newly-renovated portion of the structure, leaving more than 120 people dead along with the more than 60 people on the plane who were killed.
Army Sergeant Major Aubrey Butts was one of the scores of rescue workers who plunged into the flaming gash. He says it was like walking into hell.
"When you looked at the destruction in there, it was like walking into hell. ... The twisted metal, the intense heat and you just looked and you knew it was horrific for the people that were in there," he said.
In the wake of the attacks on the Pentagon and the World Trade Center in New York, officials quickly pointed the finger of blame at al-Qaida terrorist leader Osama bin Laden, and U.S. military attention focused on his sanctuary in Afghanistan. President Bush vowed to pursue and capture or kill the terrorists who were responsible as well as their Taleban backers.
"We're going to find ... those evil-doers, those barbaric people who attacked our country, and we're going to hold them accountable, and we're going to hold the people who house them accountable, and the people who think they can provide them safe havens will be held accountable, the people who feed them will be held accountable and the Taleban must take my statement seriously," said President Bush.
But the Taleban refused to hand over bin Laden, and less than a month after the terrorist attacks, American forces launched a series of airstrikes and other actions against targets in Afghanistan.
Defense Secretary Donald Rumsfeld recalled the sequence of military events.
"First we wanted to clear out the air defenses and the aircraft to the extent we could so we could operate over the country at some altitude successfully," said the nation's defense chief. "Second, we hit a broad range of military targets, command and control, airports, and the like, airfields. And third, we have been concentrated on [aiding] the forces that are opposing [the Taleban], the Northern Alliance and other ground forces that oppose Taleban and al-Qaida."
The military operation ultimately involved a bizarre mix of some of the most sophisticated military technology along with some decidedly old-fashioned tactics. While unmanned missile-toting reconaissance drones tracked terrorist movements from the air and supersonic jets dropped precision-guided munitions, some U.S. Special Forces on the ground joined anti-Taleban fighters in chasing terrorists on horseback.
General Richard Myers, Chairman of the Joint Chiefs of Staff of the armed forces, called the anti-terrorist operation known as Enduring Freedom the most significant U.S. combat effort since World War II.
"I firmly believe that this is the most important tasking the U.S. military has been handed since World War II," said Gen. Myers. "And what's at stake here is no less than our freedom to exist as an American people. So there's no option but success. We owe it to our families, and to the families of peace-loving nations to prevail in this fight."
In just some 11 weeks, the U.S.-led attack defeated the Taleban and virtually destroyed al-Qaida.
But al-Qaida leader bin Laden and the Taleban's Mullah Mohamed Omar remained unaccounted for. Some officials thought bin Laden might be dead. Others thought he might have escaped.
Mr. Rumsfeld said only it was a mistake to think al-Qaida was finished. "They certainly aren't functioning well. They're running and they're hiding and they're having difficulty communicating with each other. But a large number of them seem to behave in a fanatical way, and I suspect that we'll hear more of them," said Secretary Rumsfeld.
So as the year drew to a close, U.S. forces in Afghanistan remained locked in a search for bin Laden and the remnants of al-Qaida.
And there was already intense speculation under way as to where the next targets in the global war on terrorism might be. Among the candidate countries frequently mentioned were Somalia, Yemen, the Philippines and Iraq.
Part of VOA's Year End Series for 2001