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To estimate the size of the entire de facto defense budget, I gathered data for fiscal 2006, the most recently completed fiscal year, for which data on actual outlays are now available. In that year, the Department of Defense itself spent $499.4 billion. Defense-related parts of the Department of Energy budget added $16.6 billion. The Department of Homeland Security spent $69.1 billion. The Department of State and international assistance programs laid out $25.3 billion for activities arguably related to defense purposes either directly or indirectly. The Department of Veterans Affairs had outlays of $69.8 billion. The Department of the Treasury, which funds the lion’s share of military retirement costs through its support of the little-known Military Retirement Fund, added $38.5 billion. A large part of the National Aeronautics and Space Administration’s outlays ought to be regarded as defense-related, if only indirectly so. When all of these other parts of the budget are added to the budget for the Pentagon itself, they increase the fiscal 2006 total by nearly half again, to $728.2 billion.
To find out how much of the government’s net interest payments on publicly held national debt ought to be attributed to past debt-funded defense spending requires a considerable amount of calculation. I added up all past deficits (minus surpluses) since 1916 (when the debt was nearly zero), prorated according to each year’s ratio of narrowly defined national security spending—military, veterans, and international affairs—to total federal spending, expressing everything in dollars of constant purchasing power. This sum is equal to 91.2 percent of the value of the national debt held by the public at the end of 2006. Therefore, I attribute that same percentage of the government’s net interest outlays in that year to past debt-financed defense spending. The total amount so attributed comes to $206.7 billion.
Adding this interest component to the previous all-agency total, the grand total comes to $934.9 billion, which is more than 87 percent greater than the Pentagon’s outlays alone.
If the additional elements of defense spending continue to maintain the same ratio to the Pentagon’s amount—and we have every reason to suppose they will—then in fiscal year 2007, through which we are now passing, the grand total spent for defense will be $1.028 trillion. I confirmed the rough accuracy of this forecast by adding up the government’s own estimates of fiscal 2007 outlays for the various additional defense-related items, obtaining a total of $987 billion—an amount only 4 percent less than my ratio-based estimate. Future defense-related supplemental appropriations for fiscal 2007, which would hardly be surprising, might easily bring the lower estimate up the higher one.
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http://www.independent.org/newsroom/article.asp?id=1941