Most if not all of the Republicans are opposed to President Obama ending the Iraq War as well as the forthcoming end to the Afghanistan War. But, via Ezra Klein, the CBO says that reducing our military forces in those theaters would reduce the deficit by $1.1 trillion over the next 10 years.
"...the number of military personnel deployed for war-related purposes would decline over a five-year period to an average of 180,000 in 2011, 130,000 in 2012, 100,000 in 2013, 65,000 in 2014, and 45,000 in 2015 and thereafter. Under this scenario, total discretionary outlays over the 2012–2021 period would be $1.1 trillion less than the amount in the baseline. Debt-service costs would bring the cumulative savings relative to the baseline to about $1.4 trillion over the coming decade."
But the Republicans don't want that. And they were the ones cheerleading the whole ordeal in the first place, costing us trillions of dollars and thousands of American lives.