(FORTUNE Magazine) - Three years after U.S. forces invaded Iraq and toppled the regime of Saddam Hussein, the cost--in both lives and dollars--continues to mount.

More than 2,400 Americans have been killed and another 17,000 wounded since the war began on March 19, 2003. Suicide bombings like this one in a restaurant in Mosul in February, where five people were killed, are not abating. Unofficial estimates of Iraqi deaths range from 15,000 to 100,000. The U.S. Congress has appropriated $301 billion for military operations in Iraq, according to the Congressional Research Service--a far cry from the $50 billion Donald Rumsfeld estimated the war would cost Americans in early 2003.

Put another way, the Department of Defense will have forked over about $100,000 to fight the war in Iraq in the 30 seconds it takes to read this.

But the total cost of the Iraq war to taxpayers could be many times higher. The Congressional Budget Office estimates the tab will increase by at least another $266 billion, assuming it takes a decade to reduce troops and wind down the war effort. Then there are the indirect costs, which, according to Columbia University economics professor Joseph Stiglitz, could boost the total to about $1.2 trillion.

Stiglitz counts mounting expenses such as ballooning veteran disability and medical payments, replacement costs for equipment and weapons, the need for extra military recruitment staff, and pumped-up bonuses paid to soldiers who re-enlist. Adding such macroeconomic factors as the impact on the workforce of lives lost and the run-up in oil prices--none of which are included in Washington's accounting--the final bill, Stiglitz says, could end up as high as $2.2 trillion.