Whether troop levels increase in coming months, or decrease, or stay the same, one aspect of the US military effort in Iraq is unlikely to change: It will be expensive.
The cost of combat in Iraq has now surpassed $300 billion, according to government estimates. Add in activities in Afghanistan, and the total price of the global war on terror is about $500 billion, making it one of the most monetarily costly conflicts in which the nation has ever engaged.
Now the Department of Defense is in the process of drawing up its follow-on request for the remainder of FY 2007. Reports indicate that the Pentagon could ask for $120 billion to $160 billion, which would be its largest funding request yet for the global war on terror.
After they take control of Congress next year, Democrats will almost certainly investigate both the rate of Iraq spending and the manner in which it has been appropriated. Much of the war has been funded through supplementals, so-called emergency bills whose use in this case has become increasingly controversial in Congress.
"We're now at $507 billion for the global war on terror and counting, and almost all of that has been pushed through a process that doesn't give proper scrutiny to the budget. Are we spending it wisely?" says Gordon Adams, a fellow at the Woodrow Wilson International Center who was the senior White House official for national security budgets under President Clinton.
Last month, Congress approved $70 billion in spending intended to pay for operations in Iraq and Afghanistan through the first six months of fiscal 2007, which began Oct. 1 for the US government.
The size of the request under discussion reflects both the continued nature of the mission and past wear-and-tear. Both the Army and the Air Force need billions to replace expensive hardware worn out by the pace of warfare in Iraq.
Before the invasion of Iraq, the White House estimated that combat operations there would cost about $50 billion. That forecast, however, was based on a quick end to the war and a rapid drawdown of US troops.
Three years later, Iraq alone is costing the US some $8 billion a month.
Estimates of total spending vary, due to the fact that Department of Defense records on obligations do not provide comprehensive specifics, and the supplemental bills voted by Congress do not have the line-item details of regular sending bills.
Congressional Research Service figures puts the cost of Iraq, Afghanistan, and other war-on-terror activities at $507 billion. Of that, the Afghan campaign has cost at least $88 billion, according to CRS. Iraq accounts for the bulk of the rest.
The drain of continued fighting in Iraq has meant that the global war on terror has steadily moved up the list of the most costly conflicts in US history (in terms of money, not casualties). In 2005, it passed the Korean war's inflation-adjusted cost of $361 billion.
Next year it will almost certainly pass the Vietnam War's $531 billion, making it the second most expensive US war ever, behind World War II.
Given the uncertainty of troop levels, it is very difficult to estimate the US military's future costs in Iraq.
Overall, each individual soldier deployed in Iraq for a year costs about $275,000, according to CRS. The cost rises to $360,000 if required additional investments in equipment and facilities are added.
Using a scenario in which US troop levels fall to 73,000 by 2010, and then stay at that level, the Congressional Budget Office estimates that the cumulative cost of the global war on terror could reach $808 billion by 2016.
Meanwhile, the Pentagon and the Bush administration have continued the practice by which funding for the war on terror is requested in the form of supplemental appropriations. Supplementals are prepared much closer to the time when the money will actually be spent. The Vietnam War, for instance, was funded via supplementals at its outset. Later, Vietnam costs were folded into the regular budget process.
Supplementals provide much less detail as to where money will be spent than do regular budget documents, and receive less congressional oversight than do regular budget bills.
So far, the White House has shown little inclination to fund Iraq and Afghanistan via the regular budget, despite some pressure from Congress to do so. In addition, the nature of items paid for via these war spending bills may have begun to expand, to include items related to peacetime missions as well.
A Democratic-controlled Congress will almost certainly look for ways to increase pressure on the White House to abandon the flexibility and opaqueness of the emergency bill approach.