The price of the war-fighting and security responses to bin Laden account for more than 15 percent of the national debt incurred in the last decade--a debt that is changing the way our military leaders perceive risk. "Our national debt is our biggest national-security threat," Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, told reporters last June.

All of those costs, totaled together, reach at least $3 trillion. And that's just the cautious estimate. Stiglitz and Bilmes believe that the Iraq conflict alone cost that much. They peg the total economic costs of both wars at $4 trillion to $6 trillion, Bilmes says. That includes fallout from the sharp increase in oil prices since 2003, which is largely attributable to growing demand from developing countries and current unrest in the Middle East but was also spurred in some part by the Iraq and Afghanistan conflicts. Bilmes and Stiglitz also count part of the 2008 financial crisis among the costs, theorizing that oil price hikes injected liquidity in global economies battling slowdowns in growth--and that helped push up housing prices and contributed to the bubble.

Most important, the fight against bin Laden has not produced the benefits that accompanied previous conflicts. The military escalation of the past 10 years did not stimulate the economy as the war effort did in the 1940s--with the exception of a few large defense contractors--in large part because today's operations spend far less on soldiers and far more on fuel. Meanwhile, our national-security spending no longer drives innovation. The experts who spoke with National Journal could name only a few advancements spawned by the fight against bin Laden, including Predator drones and improved backup systems to protect information technology from a terrorist attack or other disaster. "The spin-off effects of military technology were demonstrably more apparent in the '40s and '50s and '60s," says Gordon Adams, a national-security expert at American Univeristy.

Another reason that so little economic benefit has come from this war is that it has produced less--not more--stability around the world. Stable countries, with functioning markets governed by the rule of law, make better trading partners; it's easier to start a business, or tap national resources, or develop new products in times of tranquility than in times of strife. "If you can successfully pursue a military campaign and bring stability at the end of it, there is an economic benefit," says economic historian Joshua Goldstein of the University of Massachusetts. "If we stabilized Libya, that would have an economic benefit."

Even the psychological boost from bin Laden's death seems muted by historical standards. Imagine the emancipation of the slaves. Victory over the Axis powers gave Americans a sense of euphoria and limitless possibility. O'Hanlon says, "I take no great satisfaction in his death because I'm still amazed at the devastation and how high a burden he placed on us." It is "more like a relief than a joy that I feel." Majewski adds, "Even in a conflict like the Civil War or World War II, there's a sense of tragedy but of triumph, too. But the war on terror ... it's hard to see what we get out of it, technologically or institutionally."