Following the death of Osama bin Laden, does the U.S. now face a greater risk of a terrorist retaliation from al-Qaida?

Bin Laden's death could trigger a backlash against Americans and other Westerners by those who had strong feelings of affinity for the al-Qaida leader. He remained hugely popular in much of the Middle East. This does not mean that everyone who favored him will rush to violence. But to some of his followers, a symbol of Islamic extremist strength has been vanquished. Individuals or networks who saw themselves as bin Laden fellow travelers could look to take revenge.
Still, al-Qaida as an institution is unlikely to be in a position to organize a sophisticated counter-response to bin Laden's death, at least for the time being. Al Qaida's style is to run well-organized operations that involve complex moving parts which simultaneously converge on a high profile target. In recent years, as the U.S. and its allies have disrupted al-Qaida's networks, it has had an increasingly difficult time organizing sophisticated attack outside the South Asia/Middle East region. It's unlikely that al-Qaida could organize something large scale in the short term.

What does this mean for al-Qaida's future? Will it fade away?

Osama bin Laden and his second-in-command, Ayman al-Zawahiri, had become symbolic rather than command and control leaders over al-Qaida assets in recent years. Killing bin Laden removes the symbol, but he could become a rallying martyr in the eyes of some extremists. There are well-organized, potent operations that have affiliated with al-Qaida in Yemen, in North Africa, and elsewhere in the region. They will no doubt continue their operations, at least for the near term. But this is a blow for them.
What is known about the Ayman al-Zawahiri, al-Qaida's No. 2?

Al-Zawahiri, the Egyptian cleric who remains at large, was an operational and strategic force in building and animating al Qaeda alongside bin Laden. He now becomes the most wanted terrorist in the world. There have been many attempted strikes and near misses against al-Zawahiri, some killing close family members of his. Emboldened by the success against bin Laden, the US will undoubtedly try to maintain momentum. Enormous intelligence efforts will be focused on tracking and either capturing or killing al-Zawahiri.

What does this mean to the image of the U.S. in the world? Where does the U.S. gain? Where does it lose?
The killing of bin Laden removes one of the elements that made America look impotent in the eyes of much of the world. Bin Laden killed thousands of Americans on US soil. The US has responded by spending trillions on its security and various wars since, but has not been able to bring to justice the top perpetrators of 9/11. This is a huge gain, symbolically, for the US, but challenges remain.
The downside risk really rests with Pakistan. Did Pakistan really not know that Osama bin Laden was residing 35 miles north of its capital? What is the future of joint operations with Pakistan, if we learn that military or government officials were complicit in hiding bin Laden? Pakistan, a nuclear-armed fragile Islamic nation, is of near unparalleled strategic importance to the US in this region. The downside of killing bin Laden is that it will compel all parties to ask very tough, hard questions of who knew what, when—and then deal with what are likely extremely uncomfortable realities.

Anti-Americanism had already been rising in Pakistan. Will this help or hurt the willingness of Pakistan to cooperate in the fight against extremism?

In the near term, the killing of bin Laden will shake a fragile Pakistan. The U.S. will win some support, but also a lot of condemnation. In much of Pakistan, Osama bin Laden was a rock star, a pop culture symbol of what many in this region considered to be "righteous terrorism". Those who believed strongly in bin Laden will feel a loss for some time and will be angry at the U.S. and the West.

How about the broader war on terrorism? How significant is bin Laden's death?

Killing bin Laden is huge symbolically—but of questionable impact when it comes to ending the broad trend of well-organized transnational terrorism. To some degree, the various al-Qaida affiliated networks learned to organize operations without the instruction and support of bin Laden and al-Zawahiri long ago. They will continue to function, and there is always the chance that others will attempt to assert themselves as "the next bin Laden."
But knocking out the top symbol of al-Qaida gives the US a chance to declare success and potentially begin to draw down some forces in Afghanistan.

What will it mean for the war in Afghanistan?

Bin Laden's death will affect the war in Afghanistan in the sense that the hunt for him was one of the primary rationales for the invasion. There was no narrative available to the U.S. and international forces deployed in Afghanistan to leave unless they had dealt definitively in some way with bin Laden and al-Zawahiri. Now that task is half done. Bin Laden's death does not mean that the US will now draw down forces—but at least the option exists to redeploy some units there while declaring some success.

What are the political implications for President Obama?

This is the prize George W. Bush wanted and couldn't achieve before the end of his term. The killing of bin Laden shores up Barack Obama's hard power credentials and will force political opponents like Donald Trump and Sarah Palin to change their talking points. President Obama approached the bin Laden challenge seriously, cautiously, and showed a focused earnestness in bringing him to justice. This will boost President Obama for some time and puts much more solid ground beneath his 2012 presidential run.