The Pentagon's base budget has increased substantially due to the post-9/11 wars, over and above the amounts appropriated for Overseas Contingency Operations, the war fund. For instance, non-emergency, base budget appropriations have included rising personnel pay and benefits, weapons procurement, and funding for military bases.
Unfortunately, because the Pentagon has not done a competent or transparent accounting for these and other appropriations, we have no reliable assurance of how, or even where, the funds were actually spent.
This additional spending is most plausibly explained by the political dynamics of the post-9/11 wars that have translated into Congressional support, not just for war funding, but for the broader Department of Defense budget as well.
Congress should require the Department of Defense Inspector General to conduct a comprehensive audit of the actual amounts of all federal funding spent on the post-9/11 wars, and should make the report publicly available.
(Page updated as of September 2021)