According to the diligent work of the Congressional Research Service, we know that the U.S. Congress appropriated $1,208 billion in current dollars through fiscal year 2011 to the Department of Defense (DOD) for the post-9/11 wars. Using the Pentagon's own deflators, this is $1,313 billion in 2011 constant dollars.

These Pentagon appropriations address not just the conflicts in Iraq and Afghanistan; they also include DOD costs for many other war-related operations and programs in other countries, such as Pakistan, the Philippines, Yemen, Djibouti and elsewhere, and they include Operation Noble Eagle for anti-terror security in the US.

Unfortunately, because the Pentagon does not competently account for appropriations to it, according to decades of reports from the Government Accountability Office and the Department of Defense's own Inspector General, we have no reliable assurance of how, or even where, the funds were actually spent.

In addition, Pentagon managers and Congress permitted appropriations ostensibly for the wars to actually address expenses that were only marginally related to the wars (and in some cases hardly at all).  For this reason and because some expenses in routine, non-war, DOD appropriations were induced by the wars, the actual amounts of all war expenses might come to a significantly different total.  No such audit has yet been required by Congress or any other entity.

Since 2001, in addition to the $1,313 billion in 2011 constant dollars spent for the wars, $5,238.7 billion  in constant dollars was appropriated for ostensibly non-war DOD expenses (also known as the “base” DOD budget) up to the end of 2011.  To the extent that long range Pentagon budget planning just before 9/11 can be deciphered, a pre-war “baseline” trajectory of spending can be established.  This report’s calculation of that baseline spending is $4,572 billion for fiscal years 2001-2011. 

Thus, the DOD “base” budget grew over the discernable pre-war 2001 plan by $667 billion in 2011 dollars ($616 billion in “current” dollars).  This additional spending was politically driven by “support the troops” campaigns that translated into not just support for war funding but for the broader DOD budget as well.  Any efforts to reduce the base budget, or even to hold it steady, would predictably run into arguments like those of Congressman Buck McKeon (R-CA), current Chair of the House Armed Services Committee, that it is unthinkable to refuse growth to the defense budget while we are "at war."  As the report’s author, a participant in congressional debates on the defense budget for over 30 years, observed, the defense budget grew not just in the war-related accounts but in the “base” budget as well, and that “base” budget growth was an artifact of the wars.

The $667 billion in 2011 dollars appropriated to the Defense Department's base budget since 2001 is clearly a result of the political dynamics of the post-9/11 wars; it should be counted as an additional, albeit indirect, cost of the wars and should be included in any comprehensive attempt to capture the total cost of the wars. 

This analysis would bring the total DOD costs of the wars to $1.98 trillion in constant 2011 dollars using Pentagon deflators.