Using a standard macroeconomic model of the US economy, Ryan Edwards estimates that as of 2014, the US has already incurred an additional approximately $453 billion in interest on borrowing to pay for the wars. Over the next several decades, assuming no more military spending on these wars, but also no additional tax increases or spending cuts, cumulated interest costs on borrowing to pay for the wars will ultimately rise to dwarf the $1.5 trillion of direct military spending from 2001-‐‑2013, adding more than $7.9 trillion to the national debt.71 Thus, although military spending may not continue to rise over the next 40 years, interest costs will surpass total war costs unless Congress devises another plan to pay for the wars.