If the al-Qaida terrorists who slammed a hijacked jetliner into the Pentagon one year ago had hoped to cripple America's military, even symbolically, then by most measurements they failed miserably.
Though 125 people who worked in the massive building were killed, the section of the Pentagon destroyed in the attack has been rebuilt. The rapid reconstruction project, dubbed Operation Phoenix, has put uniformed and civilian personnel back to work in newly-refurbished offices at the point of the commandeered plane's impact.
As for the terrorists themselves, beyond the five hijackers killed at the Pentagon, those others who have not been killed elsewhere are on the run - the result of Operation Enduring Freedom. The series of U.S. counter-attacks against terrorist bases in Afghanistan that was launched less than a month after September 11.
The counter-strikes were the fulfillment of a vow made by President Bush after visiting the Defense Department just days after the terrorist attack.
"We are going to find those who, those evil-doers, those barbaric people who attacked our country," he said. "And we are going to hold them accountable, and we are 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."
The U.S. operation involved a bizarre mix of some of the most sophisticated military technology along with some decidedly old-fashioned tactics. While unmanned missile-toting reconnaissance 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 operation 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 the Second World War," he said. "And what is at stake here is no less than our freedom to exist as an American people. So there is 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 11 weeks, the U.S. led attack defeated the Taleban and virtually destroyed al-Qaida.
But the operation drew criticism, in part because there have been some civilian casualties, but more so because al-Qaida leader Osama bin Laden and the Taleban's Mullah Mohamed Omar remained unaccounted for.
Some officials believe bin Laden might be dead. Others think he may have escaped.
Mr. Rumsfeld says only it was a mistake to think al-Qaida is finished.
"And I would think that it would be a mistake to say that the al Qaeda is finished in Afghanistan at this stage," he said. "They certainly are not functioning well. They are running and they are hiding and they are having difficulty communicating with each other. But a large number of them seem to behave in a fanatical way, and I suspect that we will hear more of them."
In the meantime, though, the Pentagon is taking time this September 11 to remember the victims of the attack a year ago. Defense officials say the ceremony, to be attended by President Bush, will of course acknowledge the dead, the injured, and their friends and relatives.
But it will also honor the work crews who beat their own self-imposed deadline to rebuild the Pentagon's damaged portions.
One senior official says the main message to world will be a clear one: that the U.S. armed forces, joined by officials from other agencies along with foreign coalition partners, are prosecuting a war vigorously against those responsible for such terrorist attacks and those who support them.