With bin Laden dead, should the war in Afghanistan die with him?

The killing of Osama bin Laden will reshape the Obama administration's ongoing fight against al Qaeda and other terror groups by ridding the United States of its primary battlefield target. But it could have an even bigger impact on public support for the Afghan war itself, as many Americans take bin Laden's death as a sign that the United States has accomplished its mission in Afghanistan and should now begin winding down the unpopular conflict.

Bin Laden has loomed large in the history of modern Afghanistan, which was in many ways the fugitive Saudi national's adopted homeland. Bin Laden made his name raising money and leading Islamist fighters in the bloody effort to defeat the Soviet Union there. More recently, Afghanistan was al Qaeda's operational base in the run-up to the September 11 attacks. U.S. forces invaded the country in the immediate aftermath of the terror strikes, beginning a grinding guerrilla war that has now lasted almost a decade and caused more than 1,560 American battlefield deaths. Last year was the deadliest stretch of the war for American and NATO troops, and 2011 -- with 160 fatalities so far, including 120 U.S. deaths -- is on pace to set a grim new record.

When the Obama administration sent 30,000 reinforcements into Afghanistan last year, the president and his top advisers said the escalation was primarily designed to destroy any al Qaeda remnants in the country and to prevent the armed group from returning to the safe havens it had used there to plan the September 11 attacks. "Our overarching goal remains the same: to disrupt, dismantle, and defeat al Qaeda in Afghanistan and Pakistan and to prevent its capacity to threaten America and our allies in the future," Obama told a crowd of cadets at West Point in December 2009 when he announced his plans to deploy the additional American forces.

Since the American surge troops poured into Afghanistan last summer, the American military has made some gains against the Taliban, the armed group which sheltered al Qaeda in the years before the terror strikes. But despite scattered reports of some low-ranking al Qaeda operatives returning to remote parts of Afghanistan, American military and intelligence officials have long conceded that the primary battlefield in the war against al Qaeda lies in neighboring Pakistan, not in Afghanistan. The administration has sharply escalated its drone campaign in Pakistan, increasing the number of strikes from 35 in 2008, the year before Obama took office, to 117 last year and at least 21 so far this year. In ordering the high-stakes Navy Seal assault on bin Laden's compound in a leafy suburb of Islamabad, meanwhile, Obama has also kept his campaign promise to send American combat troops into Pakistan unilaterally if the U.S. had actionable intelligence about the al Qaeda chieftain's whereabouts.

The White House is getting ready to launch a far-reaching review of the U.S. war effort in coming weeks as part of a broad push to decide how many of the surge troops to bring home by its self-imposed July deadline. As recently as last March, high-ranking military officers told National Journal in interviews that they expected Obama to order a token withdrawal of only a few thousand military personnel, largely support forces and other non-combat troops. But even before bin Laden's death on Sunday, those same officers said their discussions with senior White House aides in recent weeks had convinced them that Obama was leaning toward ordering a far larger withdrawal, possibly as many as two brigades, or roughly 10,000 troops. With bin Laden now out of the picture, the White House may feel even freer to order a larger drawdown than most in the military would prefer.

"There are widespread public beliefs (even if neither of these beliefs is really correct) that: (1) the fight in Afghanistan is all about fighting al Qaeda and preventing another 9/11; and (2) Osama bin Laden is what al Qaeda is all about," said Paul Pillar, who was the deputy chief of the CIA's counterrrorist center from 1997 to 1999 and now directs the graduate studies program at Georgetown University's Center for Peace and Security Studies. "The effects of this event on opinion probably will give President Obama somewhat more running room to scale down the military effort in Afghanistan more extensively and more rapidly than he might otherwise have been able to do."

Indeed, bin Laden's killing will put supporters of maintaining the current U.S. war strategy on the defensive during the upcoming White House Afghan review by underscoring that the center of gravity for the broader war on terror has long ago shifted away from Afghanistan, which means that the troops now stationed there could perhaps be better utilized elsewhere. At the same time, it is likely to strengthen the hand of Vice President Joe Biden and several other senior White House officials who have long argued that the U.S. should shrink its footprint in Afghanistan, abandon its manpower-intensive counterinsurgency approach there, and instead use CIA paramilitary operatives and elite Special Operations forces like the Navy Seals to mount targeted counter-terror strikes inside both Afghanistan and Pakistan.

CIA Director Leon Panetta, who was tapped last week to succeed Robert Gates at the Pentagon, largely shares Biden's beliefs, and the administration's restructuring of its national-security team removes the architects of the current Afghan war strategy and replaces them with officials who are less wedded to the notion of maintaining the robust counterinsurgency campaign and perhaps more willing to contemplate a deeper and faster military withdrawal from the country. Killing bin Laden, who has been the sole reason many Americans supported the Afghan war in the first place, could provide new impetus for a bigger withdrawal this summer.

"Since the rationale for the war in Afghanistan has always been justified as a necessary response to the September 11 attacks, many Americans will now believe that purpose has been achieved and it is time for U.S. forces to come home," said Nora Bensahel, the senior fellow and deputy director of studies at the Center for a New American Security. "Obama will face an uphill battle convincing Americans -- and some members of Congress -- that U.S. strategic interests still require spending billions of dollars a month on military operations in Afghanistan."

The x-factor in all of this is the possibility of al Qaeda mounting a new attack inside the United States as revenge for bin Laden's death. If a successful al-Qaida strike is traced back to Afghanistan or Pakistan, the entire political calculus surrounding the war would shift again, which could lead Obama to maintain roughly the current U.S. troop levels there well into the future. Al Qaeda has threatened new attacks inside the U.S. for nearly a decade but consistently failed to pull one off, so its far from a sure thing that the group -- even if it now has even more motivation -- will be able to carry out such a retaliatory strike. But if the events of the past 48 hours have taught us anything, it's that wars fought thousands of miles away from the mainland U.S. can result in sudden victories -- and, potentially, sudden defeats as well.