If World War II brought America out of the Depression, the post-9/11 "War on Terror" threatens to drag the country into one. So goes the conventional wisdom a decade after the life-changing attacks on the United States.

The nation has paid a dear price in blood and treasure to hunt down the terrorist organizations that hijacked four commercial jetliners and toppled the World Trade Center towers in New York City.

In addition to the 2,752 lives lost in the Sept. 11, 2001, attacks, more than 6,000 U.S. military personnel have been killed in Iraq and Afghanistan. According to estimates, wartime operations directly resulted in the deaths of 224,000 to 258,000 people, including 125,000 Iraq civilians.

The economic cost to America is harder to quantify, and no less disturbing.

Through 2012, the Congressional Research Service pegged the estimated cost of war funding at $1.4 trillion. But that figure has been called unduly conservative.

"I don't know what the president knows, but I wish it were a trillion," Boston University professor Neta Crawford told Reuters.

A Brown University report co-directed by Crawford estimates that $3.7 trillion to $4.4 trillion has been spent on wartime expenses, mostly on military missions in Iraq and Afghanistan. Going forward, the report projected these costs:

• Anticipated benefits for veterans through 2050: $589 billion to $934 billion.
• Additional Pentagon appropriations: $326 billion to $652 billion.
• Projected war-related spending between 2012 and 2020: $453 billion.
• Homeland Security spending: $401 billion.
• "Social costs" paid by service members and their families: $295 billion to $400 billion.
• Interest payments for debt incurred from borrowing for war spending: $185 billion.
• War-related foreign aid: $74 billion.

Joseph Stiglitz, a Columbia University economist, calculated the costs between $3 trillion and $5 trillion -- and that was three years ago.

"With almost 50 percent of returning troops eligible to receive some level of disability payment, and more than 600,000 treated so far in veterans' medical facilities, we now estimate that future disability payments and health care costs will total $600 billion to $900 billion," Stiglitz wrote in a book, "The Three Trillion Dollar War," co-authored with Linda Bilmes.

"The social costs, reflected in veteran suicides (which have topped 18 per day in recent years) and family breakups, are incalculable," Stiglitz said.

Stiglitz argues that the post-9/11 military operations have contributed to America's "macro-economic weaknesses, which exacerbated its deficits and debt burden."

Among the ill-effects cited by the Nobel Prize-winning economist:

'WAR ECONOMY' MAKES LESS EFFICIENT USE OF RESOURCES

While defense contractors have profited -- for example, Sikorsky Aircraft Corp., the maker of Black Hawk helicopters, saw its global sales more than double in

five years to $6.7 billion in 2010 — the benefits have not trickled down.