This time three years ago, the country was celebrating the killing of Osama bin Laden. "The death of bin Laden marks the most significant achievement to date in our nation's effort to defeat al Qaeda," President Obama said in a May 2, 2011, address to the nation.
"We will never tolerate our security being threatened, nor stand idly by when our people have been killed," Obama said.
It's all well and good to mark the achievement of finding and killing bin Laden, as well as the capture or elimination of other top al Qaeda leaders.
But today, three years after the bin Laden raid and few months shy of the 13th anniversary of the Sept. 11, 2001, terrorist attacks, there are still significant players in 9/11 who remain at large.
American leaders have a solemn responsibility to track them down. When is that going to happen?
The major figure is Ayman al-Zawahiri, al Qaeda's No. 2. who took over the organization after bin Laden's death.
He was deeply involved in Sept. 11 -- sometimes called the "operational brains" of the attack -- and, like bin Laden, managed to escape U.S. attacks in Afghanistan by fleeing to Pakistan, where he is believed to still be hiding out. The U.S. is offering a $25 million reward for information leading to his capture.
There is some debate over just how involved Zawahiri is in al Qaeda's operations today. "He is still very much operationally involved, even though there are challenges to authority," says Tom Joscelyn, who tracks al Qaeda for the Foundation for Defense of Democracies. "He still has several branches of al Qaeda that are loyal to him, and he is still communicating with them."
These days, Zawahiri is making trouble in Syria, which has plenty of trouble without him. But even if Zawahiri were doing nothing, it is still the United States' responsibility to punish him for Sept. 11.
"This administration has no appetite for detention and interrogation," says Charles "Cully" Stimson, a former Bush Defense Department official now at the Heritage Foundation. "They don't like it and haven't developed an expertise at it."
Whatever. A successful drone strike on Zawahiri would be fine.
Then there is Mullah Omar, who was head of the Taliban in Afghanistan and bin Laden's host as the 9/11 attacks were plotted.
There have been many reports that Omar opposed the plan to attack America, but there is no doubt he sheltered the 9/11 perpetrators as they did their work. U.S. forces should have gotten him by now, too.
There are also lesser players, such as Nasir al-Wuhayshi, who was Osama bin Laden's personal aide. Mohammed Haydar Zammar, who recruited some of the terrorists who hijacked the planes.
And Muhsin al-Fadhli, a senior al Qaeda figure who, according to the National Counterterrorism Center, was "among the few trusted al Qaeda operatives who received advance notification that terrorists would strike the United States on September 11, 2001." (The U.S. is offering a $7 million reward for him.)
Frustration that these men are still on the loose is not a partisan issue. President George W. Bush failed to find them for seven years and four months after 9/11. The Obama administration has so far failed to find them for five years and four months. The count goes on, through Republican and Democratic rule.
"God knows Bush tried, and I suspect the bureaucracy has continued to do so under Obama, whatever the White House itself thinks. So I don't blame the failure to get the 9/11 guys on Obama as such," Bolton said.
Now, even as the search continues, Congress is ramping up the investigation into the Sept. 11, 2012 killing of four Americans, including Ambassador Chris Stevens, at the U.S. diplomatic compound in Benghazi, Libya.
The killers in that attack have not been caught or killed. It is not clear how hard the administration is trying to find them. But if Obama doesn't do it, the next president must.
Even with an attack as devastating as 9/11, and certainly with Benghazi, each year that passes means there is less public urgency to push the search forward.
Swift retribution is no longer possible for 9/11, and the clock is ticking on Benghazi. But the world needs to know that the United States will find and punish its attackers, no matter how long it takes.