Obama has repeatedly stressed the importance of language. When asked in a January 2009 interview with Al-Arabiya TV channel about the phrases Bush used, such as "war on terror" and Islamic fascism, Obama said: "The language we use matters. ... We cannot paint with a broad brush a faith as a consequence of the violence that is done in that faith's name."
Another reason for the shift in language, experts say, is precisely because the current administration wants to separate itself from its predecessor. The president hasn't shied away from that.
But does that mean the threat from bin Laden is over?
"Eliminating Osama bin Laden and Ayman al-Zawahiri won't result in a defeat of al Qaeda, but you cannot defeat al Qaeda without eliminating Osama bin Laden and Ayman al-Zawahiri," Nelson said.
Nelson's statement echoed remarks made by the top U.S. commander in Afghanistan, Gen. Stanley McChrystal, in December, when he said capturing or killing bin Laden, an iconic figure whose "survival emboldens al Qaeda as a franchising organization across the world," would help in defeating al Qaeda.
"It would not defeat al Qaeda to have him captured or killed, but I don't think that we can finally defeat al Qaeda until he is captured or killed," he told Congress.
Experts say symbolically, it is key to eliminate both bin Laden and al-Zawahiri, but doing so won't mean the threat is over.
"I think symbolically, it would mean a lot, but it would be foolish for any one of us to assume that if we got rid of both of them the threat would leave us," ABC News consultant and former FBI agent Jack Cloonan told ABC News. "It won't. They're not in charge of the organization anymore."
Cloonan, who served as a senior agent on the FBI's bin Laden squad in New York and headed the case of alleged 9/11 mastermind Khalid Sheik Mohammed, said al Qaeda as an organization has changed considerably over the years. Rather than being a united group, it exists in many shapes and forms throughout the world, a challenge the Obama administration saw firsthand in the case of the botched Christmas Day terror plot.
But that doesn't mean the United States has stopped going after the senior leadership. In fact, the case of the CIA agents being killed by a double agent in Afghanistan last month was a clear indication that the United States is still having a hard time pinning down the location of al Qaeda leaders, Cloonan said.
The Jordanian doctor who killed five CIA officers and two CIA security contractors lured the agents to a meeting by claiming he had just met with Zawahiri and bin Laden.
"It shows you how vulnerable we can be after all this time because we lack the critical information to get Zawahiri and bin Laden," Cloonan said. "It tells me also we are very dependent on liaison services to come forward with somebody who we can send into that region of the world. ... We don't have the human assets to tell us where these people are."
The president and his team may not have made bin Laden the central feature of their terrorism war -- and have been chided by critics for not using the word "terrorism" enough -- but they have upped the assault on al Qaeda. The administration approved an escalation of CIA drone strikes, mostly in North Waziristan, in northwest Pakistan, where al Qaeda leadership is believed to be hiding.